Hydro-furnaces and related methods for vehicles

ABSTRACT

A hydro-furnace for an RV includes a housing, a water inlet and a hot water outlet accessible through the housing, a radiator tank inside a radiator compartment of the housing, a heat exchanger inside a burner compartment of the housing for heating water flowing therethrough, a burner inside the burner compartment to provide heat to the heat exchanger, a heater core inside a recirculating compartment of the housing or heating air flowing therethrough, a blower inside the recirculating compartment for pulling return air through the heater core and delivering heated air outside the housing, and a pump circulating water from the radiator tank through the heat exchanger, through the heater core, and back to the radiator tank.

FIELD OF ART

The disclosed invention generally relates to a heating system and is more specifically directed to a heating system providing heated water and air and related methods for use in recreational vehicles (RVs) or utility vehicles and boats. Utility vehicles can include ambulances, fire trucks, and military vehicles where hot water and hot air is required for certain procedures.

BACKGROUND

Conventional water heaters and furnaces designed for the home or commercial buildings are typically separate components, which are bulky, heavy, and require special mounting fixtures and safety devices. For these reasons, such conventional water heaters and furnaces for the home are not portable and not suitable for use in or on mobile vehicles, such as recreational vehicles (RVs), and boats.

Because space and weight are at a premium in recreational vehicles and boats, hot water heaters utilizing large tanks and furnace systems are undesirable, but nonetheless are today universally used, notwithstanding their weight and bulky configuration. A typical tank-based water heater unit includes a burner and a tank with capacity that provides 5 to 10 gallons of hot water with recovery times ranging from 30 to 60 minutes. A typical forced air furnace with a separate burner and blower assembly also adds additional weight and occupies additional space.

Hot water heaters such as described in U.S. Pat. No. 5,039,007, which provide for both hot water and heated air for space heating purposes, have never been developed commercially. Currently most tankless water heaters and water heaters with tanks designed for recreational vehicles and boats on the US market are limited in market share due to high cost and poor performance, among others.

SUMMARY

Aspects of the invention relate to a water heater and furnace system for a recreational vehicle (RV) having a housing; a water inlet for receiving water from a water supply accessible through the housing; a hot water outlet accessible through the housing; a heat exchanger inside of the housing for heating water flowing therethrough; a burner inside of the housing to provide heat to the heat exchanger; a heater core coupled downstream of the hot water outlet of the housing; a blower for moving air through the heater core and delivering heated air outside the housing; a storage tank for storing water passed through the heater core; and a pump circulating water from the storage tank to the heat exchanger.

Some embodiments of the water heater and furnace system further comprise a one-way valve downstream of the heater core and upstream of the storage tank to prevent water from flowing from the storage tank to the heater core.

Also, embodiments can include wherein the housing is sealed off from an interior of the RV.

Additionally, embodiments can include wherein the heater core comprises a plurality of spaced apart fins configured for convective heat transfer from the water running through the heater core to the fins to heat the air.

Some embodiments of the water heater and furnace system include wherein the heater core further comprises a pneumatic resistance screen to reduce the velocity of the air moved through the blower to increase the heat transfer from the heater core to the air as the air passes through the heater core.

Also, embodiments can include a mixing valve upstream of the hot water outlet and downstream of the water inlet and the heater core.

Additionally, embodiments can further include a relay connected to the burner to prevent the burner from switching to a low setting from a high setting when the blower and the burner are both operating.

Additionally, embodiments can include an exhaust system coupled to a top end of the heat exchanger to collect combustion byproducts of the burner, and direct the combustion byproducts outside the housing.

Some embodiments of the water heater and furnace system include an air plenum to collect and deliver the heated air to heating ducts.

Also, embodiments can include a solenoid valve coupled downstream of the storage tank and configured to control flow of the water from the storage tank to the heat exchanger.

Additionally, embodiments can include a manifold attached to the storage tank, wherein the manifold is configured to convey water from the heater core to an upper region inside the storage tank.

Also, embodiments can include wherein the manifold is configured to convey the water from a lower region inside the storage tank to the pump.

Aspects of the invention relate to a method for regulating water outlet temperature and space heating of a hydro-furnace for a recreational vehicle (RV) comprising circulating supply water from a water inlet to a heat exchanger for heating water flowing therethrough, a heater core for heating air flowing therethrough, and to a storage tank with a pump; heating the water running through the heat exchanger to produce heated water; pulling return air through a heater core; and heating the return air with the heated water to produce heated air.

Embodiments of the method further include mixing the heated water with the supply water to produce hot water at a desired hot water temperature.

Also, embodiments of the method can include wherein the desired hot water temperature is 120 degrees F.

Additionally, embodiments can include monitoring the temperature of water in the radiator tank and sending a signal to the burner to turn on if the temperature of the water in the radiator tank is below 140 degrees F.

Also, embodiments of the method can include activating the pump if the temperature of the water in the radiator tank if the burner is on.

Embodiments of the method further include turning off the burner if the temperature of the water in the radiator tank is greater than 160 degrees F.

Aspects of the invention relate to a water heater and furnace system for a recreational vehicle (RV) comprising a water heater configured to heat water received from a water supply; a hydro-furnace comprising a heat exchanger and a blower, the hydro-furnace being located remotely from the water heater, the heat exchanger being coupled to the water heater by a length of pipe, and the blower being configured to move air through the heat exchanger and deliver heated air outside of the hydro-furnace; and a storage tank configured to store water passed through the heat exchanger, the storage tank being located remotely from the water heater and the hydro-furnace, the storage tank being coupled to the hydro-furnace by a length of pipe.

Additionally, embodiments can include a solenoid valve coupled downstream of the storage tank and configured to control flow of the water from the storage tank to the water heater.

The description set forth below in connection with the appended drawings is intended as a description of the presently preferred embodiments of a combination water and air heating system for a recreational vehicle (RV) provided in accordance with aspects of the present assemblies, systems, and methods.

A combination water and air heating system or “hydro-furnace” for a mobile vehicle, which can include a recreational vehicle (RV), a boat, a mobile home trailer or fifth wheel, is provided in accordance with aspects of the present disclosure. The hydro-furnace can function as both a water heater and a space heater by supplying both hot water and hot air through three basic systems: a boiler system, a recirculating system, and a radiator system. Heated water and heated air can be generated concurrently or serially. Generally speaking, the boiler system can provide a heat source for water running therethrough by combusting air and fuel, such as propane, and exhausting combustion products to provide on-demand hot water and hot water for a storage tank.

Because fuel and byproducts of fuel are involved, the boiler system can be sealed off from the recirculating system and the radiator system to prevent combustion byproducts and unused fuel from entering the RV and potentially circulating harmful gas throughout the mobile vehicle. For purposes of the following disclosure, reference is made to an RV although other mobile vehicles can use the hydro-furnace of the present disclosure.

To increase the temperature inside the RV, the recirculating system can heat return air drawn from inside the RV using the water heated in the boiler system as the heat source, and deliver the heated air back inside the RV. The radiator system can store heated water and heat the return air when hot air is desired. As described in further detail below, the boiler system can include gas and electrical controls, a burner, a heat exchanger, a water pump, water tubing and connections, and an exhaust system. The recirculating system can include a blower, a heater core, a return air port, and water tubing and connections. The radiator system can include a radiator tank, an air plenum and duct ports, and water tubing and connections. However, components of the three systems can be re-arranged within the housing of the hydro-furnace without deviating from the scope of the invention.

Each of the three systems can be contained within one or more chambers or compartments within a housing. The components contained in the housing can include gas lines, water lines, sensors, switches, mechanical and electromechanical components, and electronics for controlling the flow and operation of both the fuel and water flowing into and/or through the hydro-furnace. Note that a hydro-furnace for an RV, such as the hydro-furnace disclosed herein, is different from a portable water heater and a portable room heater, which is understood to be portable but not necessarily for the heavy duty use and more rigid requirements for RVs.

The housing can comprise a plurality of removable panels mounted together to form two or more sides of the hydro-furnace and enclose the various components inside the hydro-furnace. Any number of panels and sub-panels can be included to form the outer surface of the hydro-furnace and divide an interior of the housing into separate smaller housings or compartments to house components of each of the three systems. In some examples, one or more of the panels of the housing can be permanent or non-removable from a housing frame.

The housing can be divided into a radiator compartment at a back side or second side of the hydro-furnace and a main compartment at a front side or first side of the hydro-furnace. The main compartment can be further divided into a blower compartment and a burner compartment. The burner compartment can be located on a left side of the hydro-furnace, from the perspective of the first side looking at the second side and the blower compartment is located on a right side of the hydro-furnace.

In another embodiment, the burner compartment can be located on the right side of the hydro-furnace and the blower compartment is located on a left side of the hydro-furnace. Said differently, the burner compartment and the blower compartment can be located along a first side or a front side of the housing, and the radiator compartment can be located along a second side or a back side of the housing directly opposite the first side. The components of the radiator system, the recirculating system, and the burner system can cooperate by extending through the interior sections of the housing.

For purposes of the following discussions, the first side or front side of the housing can also be considered the front of the hydro-furnace, and the second side or back side of the housing can be considered the back of the hydro-furnace. One of ordinary skill in the art will recognize that these directional assignments to the components of the housing and the hydro-furnace are for purposes of description only as the hydro-furnace may be installed in any orientation that allows for proper operation.

The housing includes vents, input and output connectors, and interface ports for connecting the hydro-furnace to the RV. A burner inlet vent for introducing air outside of the housing into the burner compartment can be located at the front side of the housing. A burner outlet vent for channeling combustion byproducts of a burner for heating a heat exchanger, unburned fuel, and other gases outside the burner compartment can be located above the burner inlet vent at the front side of the housing. Thus, the burner inlet vent and the burner outlet vent are provided on a front side of the hydro-furnace. The burner compartment can be sealed off from the other compartments to prevent the combustion byproducts of the burner, unburned fuel, and other gases inside the burner compartment from entering the blower compartment and the radiator compartment of the housing and mixing with the heated air to be delivered inside the RV. For example, ducting can be connected to the burner outlet vent to direct the exhaust gas to the exterior of the RV.

A fuel or gas inlet for introducing fuel to the burner in the burner compartment can extend out from a third side or left side of the housing. Alternatively, the gas inlet can be located on a front side of the housing. In another embodiment, the gas inlet is located on a right side of the housing, depending on the location of the burner compartment within the housing. Again, the orientation of the various components relative to the housing is not crucial and can vary without deviating from the scope of the present invention.

A fuel or gas line can be connected to the gas inlet to supply fuel, such as propane, to the burner. The gas inlet can be a male connector but a female connector can optionally be used, in which case a gas line having a male connector tip can engage the female connector to supply fuel to the hydro-furnace. A gas tubing or line can be provided to connect the gas inlet to a gas control valve, which can be connected in line to a burner to control gas flow from a gas source through the burner of the hydro-furnace. Other valves, such as linear or equal percentage valves, are contemplated for use with the present system to regulate gas flow through the hydro-furnace.

Control of the gas control valve can be based on various sensed parameters, such as water flow, inlet and/or outlet water temperatures, and set point. In one embodiment, the gas control valve is a linear valve. In an example, the linear valve is provided by CAE, model number CPV-H2467AY, which can be used to control gas flow through the hydro-furnace. An additional valve in line with the gas control valve may be used to further control gas flow, function as an emergency shut off valve, or any desired function. The additional valve can be an on/off solenoid valve that can function as an emergency shut off valve and that can receive operating signals from an emergency cut off switch (ECO), which can be a bi-metallic switch.

The gas control valve can be connected to a microprocessor of a controller, which can be programmed to control the gas control valve based on data and signals received from sensors such as thermostats or thermistor probes. In general, the gas control valve can be an on/off valve with a high/low setting. Alternatively, an additional valve can be an on/off valve and the gas control valve can be regulated to control gas flow from a high setting to a low setting. Together, the gas control valve and the additional valve may also act as a dual emergency shut off valve when both are in the off position. In one example, the hydro-furnace may accept propane gas only, such as while travelling with propane tanks or when parked at a camp site. In another example, the hydro-furnace may accept another type of fuel that can be supplied through the gas inlet valve, such as a gas source at a camp site.

A DC connector port for powering the hydro-furnace can be located adjacent the gas inlet valve. In an example, the DC connector port is a passage or bore through the housing having a plastic ferrule or liner that allows one or more cables to pass therethrough for connections between the electric system of the hydro-furnace, including the controller or DSI board inside or adjacent to an ignition control box discussed in detail below, and the vehicle's electric system.

A water inlet for introducing water from a water supply into the radiator compartment can extend out from a fourth side or right side of the housing opposite the left side of the housing. Alternatively, the water inlet can be installed extending from the same side but from the blower compartment. A water outlet for delivering heated water out from the hydro-furnace can extend out from the fourth side or right side of the housing adjacent to the water inlet. The water inlet and the water outlet can be mounted side-by-side or one above another elevation-wise. The location of the water inlet and the water outlet is not limited, and can also be located on other sides of the housing or separately on different sides of the housing.

A voltage connector port for powering the hydro-furnace can be located adjacent the gas control valve or at some other accessible location within the housing. In an example, the voltage connector port can be a DC connector port. The DC connector port can be a passage or bore extending through the housing having a plastic ferrule or plastic liner that allows one or more cables to pass therethrough for connections between the electric system of the water heater, such as the controller, and the vehicle's electric system. The voltage connector port may also be sealed air-tight to prevent gases in the burner chamber from leaking out other than the burner outlet vent.

A first or upper return air vent and a second or lower return air vent can extend through the second or back side of the housing to allow return air outside the housing to be pulled into the blower compartment of the hydro-furnace through the radiator compartment. A heater core located in the blower compartment by a blower is provided for heating the return air. A filter, such as a HEPA filter or other high efficiency filters, can be provided at the upper return air vent, the lower return air vent, or both vents, so that the return air can be filtered before it is heated and delivered. This can also ensure cleanliness of the components in the system. The filter can be installed inside or outside of the housing. If installed outside the housing, the filter can be easily attached and detached easily from the hydro-furnace for cleaning or replacement, such as in a cartridge compartment attached to the housing.

The radiator compartment can be rectangular shaped and formed from a C-shaped radiator housing panel having a central panel and two subpanels extending from opposite edges of the central panel. A left side radiator housing panel and a right side radiator housing panel can attach to the ends of the central panel and the two subpanels of the C-shaped radiator housing panel. A radiator housing door, which comprises air vents, can attach to the remaining free ends of the two subpanels of the C-shaped radiator housing panel to cover the opening opposite the central panel of the C-shaped radiator housing panel.

The upper return air vent and the lower return air vent are located on the radiator housing door. Thus, the radiator housing door can also be the back side of the housing. An optional radiator housing divider can be positioned inside the radiator compartment to subdivide the radiator compartment into separate smaller compartments. The radiator housing divider can extend from the central panel of the C-shaped radiator housing panel to the radiator housing door between the upper return air vent and the lower return air vent to divide the radiator compartment into an upper radiator chamber and a lower radiator chamber. Thus, return air can be drawn into the upper radiator chamber through the upper return air vent and return air can be drawn into the lower radiator chamber through the lower return air vent. The lower radiator chamber can house a radiator tank to preheat the return air as further discussed below.

Adjacent the radiator compartment is the main compartment, which can polygonal shape, such as a rectangular shape, and formed from a C-shaped main housing panel having a central panel and two subpanels extending from opposite edges of the central panel. A left side main housing panel and a right side main housing panel covering the ends of the C-shaped main housing panel or, more specifically, attached to the ends of the central panel to form an enclosure. The two subpanels of the C-shaped main housing panel and a radiator housing door are attached to the remaining free ends of the two subpanels of the main housing panel to cover the opening of the C-shaped main housing panel opposite the central panel of the C-shaped main housing panel.

A main housing divider can be positioned inside the main compartment to subdivide the main compartment into the blower compartment and the burner compartment. The main housing divider can extend between the subpanels, the central panel of the C-shaped main housing panel, and the main housing door to divide the main compartment into a left compartment or the burner compartment and a right compartment or the blower compartment.

The burner inlet vent and the burner outlet vent for providing ventilation for only the burner compartment can be located on the main housing door. Thus, the main housing door can be the first or front side of the housing. The main housing divider can be provided to effectively seal the burner compartment from the blower compartment to prevent fuel and combustion by products from entering into the blower compartment.

Air passages and water lines or tubing can extend between the radiator compartment, the adjacent blower compartment, and the adjacent burner compartment through one or more cutouts defined in both of the central panels of the C-shaped radiator housing panel, the C-shaped main housing panel, and the main housing divider. The various cutouts between the central panels and other internal panels allow the components, such as cables, wires, tubing, lines, fittings, brackets, electronics, fans, etc., from each system to connect to another system. Any cutouts between the burner compartment and any other compartment to allow components to extend therethrough can be sealed with components extending therethrough to prevent gases from leaking into the blower compartment or the radiator compartment. Optionally, sealants, fire retardant fabric or cloth, or other paneling means for isolating the different compartments can be used.

The cutouts between adjacent compartments can be similarly shaped and aligned to each other. In one example, an upper first cutout, a second cutout below the upper first cutout, and a lower third cutout below the second cutout of the central panel of the C-shaped radiator housing panel can align with similarly shaped cutouts on the main housing panel. In an example, the first cutout can be rectangular, the second cutout can be circular, and the third cutout can be rectangular. The cutouts on the main housing panel therefore include an upper rectangular cutout or first cutout, a second cutout or a circular cutout below the upper rectangular cutout, and a third cutout or a lower rectangular cutout below the circular cutout of the central panel of the C-shaped main housing panel. Alternatively, a single panel can divide the radiator compartment from the main compartment so that alignment of cutouts from different panels is not necessary.

When hot water and/or hot air is desired, the hydro-furnace can be powered on to activate the electrical and electro-mechanical components of the system. If water is not already present in the hydro-furnace, water can be directed from a water supply through the water inlet into a radiator tank located in the radiator compartment and to a mixing valve located in the blower compartment. Water line pressure or from a pump can move the water through the system.

Initially, the temperature of the water in the radiator tank may be at or near the temperature of the inlet water flowing through the water inlet. Eventually, the temperature of the water in the radiator tank will increase as it circulates through the hydro-furnace. The radiator tank is configured to store the heated water and transfer heat from the stored heated water to the return air flowing past the radiator tank when the blower is on to heat the return air as discussed further below. The mixing valve can regulate fluid flow between heated water leaving the heater core and water from the water inlet. That is, the mixing valve can mix the water at the two different temperatures from the two different sources to achieve a desired downstream or outlet water temperature of the water exiting the hot water outlet. Said differently, the mixing valve can mix the water from the water inlet with the heated water from the heater core to provide hot water at the desired outlet water temperature.

In one example, the desired outlet water temperature of the hot water leaving the hydro-furnace through the hot water outlet can be 120 degrees F. Thus, the mixing valve has two inputs and one output. The mixing valve can be a manually operable control valve or an electronically adjustable control valve. The outlet water temperature can be adjusted by controlling the mixing valve. In one embodiment, a microprocessor of a controller can send signals to adjust the mixing valve to produce a desired outlet water temperature using feedback from a temperature sensor located at or near the hot water outlet.

Before hot water can be dispensed from the hot water outlet, the water inside the radiator tank can be heated to an acceptable temperature. To do so, the water can be circulated from the radiator tank by a pump, to a heat exchanger where the water is heated by a burner. The heat exchanger can be heated directly or indirectly by a burner located in the burner compartment. The burner can burn fuel fed from the gas inlet to produce combustion gases to heat the water in the heat exchanger. In one example, the fuel is liquefied petroleum (LP) gas or propane. The heat exchanger can transfer heat from the combustion gases to the water.

From the heat exchanger, the water is pumped to a heater core. At least some of the heat from the heated water in the heater core can be drawn or pulled by a blower when powered on to provide heated air. The blower can heat return air in the RV by pulling the return air past the radiator tank and through the heater core before delivering the heated air to an air plenum and back to the RV through heating ducts. Return air drawn through the lower return vent passing over the radiator tank can also transfer heat by convection to the surrounding return air. More specifically, when a heat request is generated by a room thermostat (RTS) for space heating, the blower can turn on to pull return air from the upper and lower radiator chambers of the radiator compartment through the heater core to supply heated air to an air plenum located in the radiator compartment or blower compartment.

The air plenum is connected to heating ducts extending outside the hydro-furnace. The air plenum can accumulate the hot air from the heater core at an elevated pressure to force and direct the hot air into the heating ducts, which lead air back inside the RV. In one example, the entire blower compartment can be the air plenum. Return air circulating in the lower radiator chamber can be preheated from the radiator tank to increase the efficiency of the system. When the blower is activated to generate heated air, the heater core can provide convective heat transfer from the heated water running through the tubing inside the heater core to the return air drawn in from the upper radiator chamber and the lower radiator chamber until the desired room temperature is reached, at which time the RTS can send a signal to shut off or deactivate the blower.

From the heater core, the heated water flows through a one-way valve before returning back to the radiator tank. Thus, a heating loop can be formed from the radiator tank, the heat exchanger, the heater core, and back to the radiator tank. The one-way valve can be provided downstream of the heater core to prevent water from the water inlet to enter the heater core or flow through the water outlet other than through the mixing valve. The one-way valve can ensure only heated water leaving the heater core can pass through the mixing valve.

The pump can be located downstream of the radiator tank in the blower compartment, but also can be located in the burner compartment, the radiator compartment along the heating loop, or elsewhere within the housing. In one example, the pump is an electric activated water pump controlled by a microprocessor of a control board and operated to circulate the water through the heating loop when the hydro-furnace is powered on and a temperature of the water in the radiator tank is below a minimum tank temperature to provide hot water and/or heated air.

The pump can continually circulate the water through the heat exchanger until the average temperature of the water in the radiator tank reaches a threshold temperature, such as, for example, 160 degrees F. or some different set point temperature. Once the average temperature of the water in the radiator tank reaches the threshold temperature, such as 160 degrees F., the pump and the burner can shut off. If the water in the radiator tank falls below a minimum tank water temperature, such as 140 degrees F., the pump and the burner can switch on until the average temperature of the water in the radiator tank returns back to the threshold temperature, such as 160 degrees F. Thus, the water in the radiator tank can be maintained between 140-160 degrees F.

As hot water is being dispensed through the hot water outlet, water from the water supply can enter the radiator tank to replace the dispensed hot water. Because the newly introduced water is typically lower in temperature than the temperature of the water in the radiator tank, the new combined temperature drops from the previous tank temperature. When the temperature of the water in the radiator tank falls below the minimum tank temperature, the pump and the burner are activated to generate heat and produce additional heated water until the minimum tank temperature is reached. The hydro-furnace is capable of producing hot water as hot water is continually used. Thus, the hydro-furnace can also function as a tankless water heater.

The water supply inlet and the water outlet can be in line with each other and connected with the tubing. The water supply inlet and the hot water outlet can be located externally of the housing, such as externally of the left side of the hydro-furnace of the housing for quick access by a user. The gas inlet can be located on the right side of the hydro-furnace.

Optionally, tubing and mechanical and electrical components can be located, at least in part, outside of the panels of the housing to facilitate assembly and maintenance, among other things. Incoming water or water to be heated from a water supply or source can enter the hydro-furnace through the water inlet extending out of the housing. In one example, the water inlet can be a threaded male connector for engaging a threaded female connector from a water supply. In another example, the water inlet can be a smooth pipe with or without a hose barbed end to receive a hose or tubing connected to the water supply. A clamp can further secure the hose or tubing to the water inlet.

The water inlet can have a standard fitting to readily accept a water feed line or inlet water source. For example, the water supply inlet can comprise an industry standard connection fitting for attaching to a water supply or cold water supply line. The hot water outlet similarly can comprise an industry standard connection fitting for attaching to plumbing lines that then carry heated water to user stations, such as to sinks and baths/showers located elsewhere in the RV on which the hydro-furnace for the RV is mounted. In one example, the water supply inlet and hot water outlet can include a quick connect coupling or a threaded collar.

Unlike a water heater or furnace installed in a permanent structure, such as in a home which has a generally stable water supply temperature and pressure, an RV with a hydro-furnace moves from water supply source to water supply source when on the road travelling from point A to point B, etc. The hydro-furnace for the RV should be able to produce water at the desired temperature from widely varying water supply temperatures while still maintaining a relatively small size or profile to fit within the portable environment of the RV.

The water inlet inside the housing can transition into a multi-flow fitting, such as a four way pipe fitting or a four way tee, used to combine and/or divide fluid flow. In an example, the multi-flow fitting can be four individual fittings oriented 90 degrees apart to for a four way tee. However, multiple back to back tees can be used to split the flow into multiple streams. In one example, the water inlet is coupled to a first fitting of the four way tee, a hot water return line from the heater core is coupled to a second fitting of the four way tee, the radiator tank is coupled to a third fitting of the four way tee, and a mixing valve is coupled to a fourth fitting of the four way tee via a cold water output line. Thus, the four way tee allows water from the water inlet to flow into the radiator tank and to the mixing valve, which is further discussed below.

The radiator tank is located in the radiator compartment and can store water received from the water inlet and the hot water return line. The temperature of the water inside the radiator tank can be monitored by one or more temperature sensors and maintained and controlled at an optimum tank temperature, such as between 140-160 degrees F., using control circuitries, a controller, or a control board.

As the temperature of the water inside the radiator tank increases, so does the temperature of the radiation tank. A tank emergency cutoff thermostat (TECO) for preventing the temperature of the water inside the radiator tank from increasing past a maximum tank water temperature, can be positioned on a surface of the radiator tank. In one example, the maximum tank water temperature is 170 degrees F. In another example the maximum tank water temperature can be other than 170 degrees F. In one embodiment, the TECO can be a disc thermostat that prevents the burner from firing when the temperature of the water in the radiator tank exceeds the maximum tank water temperature.

As previously mentioned, return air can be pulled by a blower located in the adjacent blower compartment, from both the upper radiator chamber, which draws the return air from outside the hydro-furnace through the upper return air vent, and the lower radiator chamber, which draws the return air from outside the hydro-furnace through the lower return air vent. In one example, the radiator tank can be located in the lower radiator chamber of the radiation compartment. Thus, the return air in the lower radiator chamber can be preheated by convective heat transfer from the radiator tank as it travels from the radiator compartment to the blower compartment.

The radiator tank can comprise a radiator tank body having a storage space configured to store the heated water, an inlet radiator cover at an inlet end of the radiator tank body, and an outlet radiator cover at an outlet end of the radiator tank body. A plurality of fins extending from the exterior of the radiator tank body may also be provided to increase convection from between the radiator tank and the return air in the radiator compartment.

The inlet radiator cover can be similar or identical to the outlet radiator cover. The inlet and outlet radiator covers can be circular and sized to fit at opposite ends of the radiator tank body to cover the interior space of the radiator tank body. A watertight seal such as an O-ring or gasket can be provided between the radiator covers and the radiator tank body. An inlet opening through the inlet radiator cover can allow water from the inlet and/or the hot water return line from the heater core to flow inside the radiator tank body. An outlet opening through the outlet radiator cover can allow water from inside the radiator tank body to flow to the heat exchanger.

A size or diameter of the inlet and outlet openings can be smaller than a size or diameter of the interior cavity or bore of the radiator tank body so that a volume of water can be maintained inside the radiator tank body. In one example, the radiator tank body can store 2-4 gallons of water. In other examples, the tank body can store a different volume of water. The location of the inlet opening and the outlet opening can affect water flow and temperature mixing inside the radiator tank body. In one example, the inlet opening can be adjacent an outer perimeter of the inlet radiator cover, and the outlet opening can be adjacent an outer perimeter of the outlet radiator cover, with the inlet opening and outlet opening diametrically opposed at opposite ends of the heat exchanger to provide a longer path through the radiator tank body. This can ensure better mixing than a shorter direct path between the inlet and outlet openings.

Water from the radiator tank can exit out the outlet and flow to the heat exchanger via a radiator tank output line. A pump can be positioned inline and downstream of the radiator tank along the radiator tank output line. In one example, the pump can be located between the heat exchanger and the radiator tank along the radiator tank output line inside the blower compartment. The pump can be a standard electric driven water pump. The pump can be controlled directly or indirectly by control circuitry. Water can be pumped out from the radiator tank to the heat exchanger where it is heated and passes through the heater core before being dispensed through the mixing valve to the water outlet and to a faucet or shower and/or return back into the radiator tank, thus forming the heating loop. The pump can actively circulate the water until the radiator tank reaches some set point, such as 160 degrees F., at which time the burner can switch off. The pump can be shut off simultaneously with the burner or a short time thereafter. In other examples, the pump can be positioned anywhere along the heating loop as described above.

A low temperature sensor (LTS) or alternatively an input temperature probe (Tin) for measuring the temperature of the water can be connected inline and downstream of the radiator tank. The LTS can be a disc thermostat that provides a heat request signal to the burner when the water temperature in the radiator tank drops below a minimum tank water temperature. The Tin can be a thermistor probe that monitors the water temperature. In one example, the minimum tank water temperature is 140 degrees F. In the illustrated embodiments, the LTS or Tin can be located downstream of the radiator tank before reaching the pump or downstream of the pump at or before the heat exchanger. Other sensors can be used or a combination of sensors can be used to read and provide input to the controller to control the burner.

The radiator tank output line can be coupled to a heat exchanger tubing. The heat exchanger tubing can wrap around the exterior of the heat exchanger, which can be a conductive body having a skirt or a plenum. The plenum and the heat exchanger tubing can be made of a conductive material, such as aluminum, copper, copper alloy, brass, brass alloys, or other conductive metals. In other embodiments, the plenum and the heat exchanger tubing may be made from other corrosive resistant materials, or plated or coated with corrosive resistant material, that are able to withstand the direct or indirect heat of the burner.

The heat exchanger tubing can wrap around the plenum so that water flows from a bottom end of the plenum, elevation-wise, towards a top end of the plenum inside the tubing, and by conduction is heated by the plenum which then heats the water running through the heat exchanger tubing, similar to a preheat. Because both the plenum and the heat exchanger tubing can be made from a conductive material, heat energy is transferred by conduction from the plenum to the heat exchanger tubing and from the heat exchanger tubing to the water running therein. As a result, the water running around the plenum inside the tubing is pre-heated before entering the heat exchanger. The water in the heat exchanger tubing then enters the heat exchanger so as to be heated by the heated gas from the burner, as further discussed below.

The plenum can have an opening with a passage extending from the bottom end to the top end. Within the plenum, a plurality of spaced apart internal fins can be located in the opening between the bottom end and the top end to provide additional heat transfer paths to the heat exchanger. In one example, the internal fins are located near the top end to provide space for the burner. The internal fins can be closely spaced or loosely spaced inside the plenum to form baffles or channels for the flow of heated air from the bottom end of the heat exchanger and then rising through the internal fins and out the top of the heat exchanger, elevation-wise. The number of internal fins and the surface area of each of the internal fins can depend on the desired heat exchange rate by convection, conduction, and radiation exchanging with the interior run line of the heat exchanger tubing.

The heat exchanger tubing passes through the internal fins and wherein U-shaped returns are provided on outer surfaces on opposite sides of the plenum to connect the parallel tubing sections in a serpentine fashion within the interior space of the plenum. Thus, the heating pipe can form continuous passes through the opposite sides of the plenum and the internal fins to maximize the heat transfer from the internal fins to the heat exchanger tubing to heat the water flowing therein. The number of fins and the total tubing length passing inside the plenum can be selected to control the residual time of water travelling through the plenum and the amount of heat transferring directly from the burner to the plenum and from the burner to the fins and then to the heat exchanger tubing.

An exhaust system comprising an exhaust conduit can be provided to collect exhaust fumes rising from the burner and direct the exhaust fumes away from and outside the burner compartment through the burner outlet vent. The exhaust system can be positioned at the top of the plenum and coupled directly to the top end of the plenum. The exhaust system can extend horizontally towards the burner outlet vent. The exhaust system can have a larger opening at the output end to provide an open flow path to the burner outlet vent for the combustion byproducts.

The exhaust system can be sealed to ensure the combustion byproducts flow directly out the burner outlet vent. An exhaust fan powered by an exhaust fan motor may also be provided to assist directing the exhaust fumes through the burner outlet vent. The exhaust fan may be connected to a microprocessor of a controller such as the DSI board explained further below. The DSI board can operate the exhaust fan motor to turn the exhaust fan on and off based on signals sent to the microprocessor from one or more sensors. For example, whenever the burner is activated to burn fuel, the exhaust fan is also activated to exhaust gas. The exhaust fan can also be activated when the burner is not in service to move air through the system for cooling or venting purposes. A vent duct may also extend away from the housing surrounding the burner outlet vent to direct the exhaust fumes away from the hydro-furnace and the RV. The exhaust fan may be located inside the vent duct instead of inside the housing.

Additional ducting may be provided to direct the exhaust gas through the burner outlet vent and out, such as out an opening to an exterior of the mobile or recreational vehicle. In some examples, an induced draft fan, a force draft fan, or both can be incorporated to move gas through the hydro-furnace.

In some examples, inlet and outlet headers are provided within the heat exchanger. For example, the heat exchanger tubing can direct inlet water to the inlet header that then separates the single inlet feed line into multiple parallel run lines inside the heat exchanger. The multiple run lines are then routed to an outlet header that then consolidates the various run lines into a single outlet line, which then exits the heat exchanger and flow into the discharge or outlet line.

The heat exchanger tubing can wrap around the plenum of the heat exchanger three times in the form of loops, such as continuous loops or in sections that are joined. In other embodiments, the heat exchanger tubing may have fewer than three loops wrapping around the plenum or more than three loops wrapping around the plenum. The length of the heat exchanger tubing and the number of loops formed or wrapped around the heat exchanger can depend on the residual time desired to route the water through the heater, the number of tie-ins needed to connect the various component, and the desired preheat, among others.

The burner can be positioned immediately adjacent the heat exchanger and provide the heating source to heat the exchanger. In an example, the burner is positioned below the heat exchanger, elevation-wise, so that hot air and combust gas generated from the burner rise through the heat exchanger. In an example, the burner can have a wide tip having multiple gas discharge holes to provide a large distributed flame profile. The tip can comprise a plurality of plate-like structures positioned side-by-side with each plate having a plurality of discharge holes formed on an edge thereof for gas flow. The tip can alternatively have a circular ring shape, a rectangular shape, an elliptical shape, a square shape, or other shaped tips provided the number of discharge holes are selected to produce sufficient BTU for a given gas type and gas pressure.

The burner can comprise a burner pad extending at least partially into the plenum through the opening at the bottom end to provide heat inside the plenum. The amount of heat provided to the plenum to heat the water circulating in the heat exchanger tubing depends on the power output of the burner. The burner generates heat by the combustion of gas. The fuel or gas is supplied to the burner through the gas inlet extending outside of the housing. The gas is directed from the gas inlet to a fuel or gas control valve, which is configured to control the flow of gas into a burner pad located beneath or at least extending partially inside the boiler heat exchanger through the bottom end of the boiler heat exchanger. In one embodiment, the gas control valve can open and operate in one of two stages: a high stage (HI) and a low stage (LO), as discussed further below. When not in use, the gas control valve can cut off the supply of gas or shut off. When the gas control valve is on HI, the output of gas is at a high BTU rating, and when the gas control valve is on LO, the output of gas is at a lower BTU rating. Alternatively, the can control valve can be a variable gas control valve.

The multiple gas discharge holes of the burner pad can be a series of nozzles for the gas to pass therethrough. An ignition control box can comprise a direct spark ignition (DSI) board having a microprocessor and ignition control electronics including a spark igniter, which can be controlled to ignite the gas leaving the nozzles to combust the gas and produce heat. The ignition control box and the gas control valve can be controlled directly or indirectly by control circuitry.

The heat exchanger tubing can exit the heat exchanger and connect to an input port of the heater core via a connector tubing. The heat exchanger tubing cam exit the heat exchanger near the top end of the heat exchanger. A boiler heat exchanger emergency cutoff thermostat (BECO) can be provided to detect whether the temperature of the water leaving the heat exchanger exceeds an absolute maximum heated temperature to cut power to the burner. In one example, the absolute maximum heated temperature is 185 degrees F. with other maximum values contemplated, such as lower or higher than 185 degrees F. The BECO can be connected inline and downstream of the heat exchanger. In one example, the BECO is a disc thermostat that turns off the burner, or sends signals to the controller to then turn off fuel to the burner, when the water temperature at the output of the heat exchanger exceeds 185 degrees F. In an example, when the max temperature is sensed, the emergency shut off valve is activated to block all fuel to the burner. When the burner is not on, the pump can also turn of. Conversely, the pump can be operational when the burner is on.

A high temperature sensor (HTS) or an output temperature probe (Tout) for monitoring the temperature of the water downstream of the heat exchanger can be placed adjacent, downstream or upstream, to the BECO to stop the burner when the water temperature at the output of the heat exchanger exceeds a maximum heated water temperature. In one example, the maximum heated water temperature can be 175 degrees F. The heater core can transfer heat from the water to the return air supplied by the blower.

The heater core comprises a core body having a box like shape mounted in the blower compartment on a panel separating the radiation compartment from the blower compartment. The core body can have a hollow rectangular shape with a rear opening facing the radiator compartment and a front opening facing towards the blower. Flanges can extend from each side of the rear opening to attach to the central panels of the radiator housing and/or main housing.

The rear opening can communicate to the radiator compartment, and more specifically, the upper and lower radiator chamber through the upper rectangular cutouts. The front opening can be coupled directly to a suction port of the blower.

The blower circulates air from the interior space of the mobile vehicle or RV through the radiator tank and the heater core to the air plenum and back to the room through air ducts. The blower has a suction port to draw in air and a blower port to blow air out. Thus, the blower can function as a vacuum. Alternatively, the ports can be reversed, or a different type of blower can be used, as desired.

A room thermostat (RTS) outside the hydro-furnace can be preprogrammed or operated by a user to generate and transmit a heat request for air heating or space heating. The RTS can be connected to control circuity of the hydro-furnace to activate the pump, the burner, and the blower when powered “ON”. The RTS can also send signals to the control circuitry of the hydro-furnace to stop the blower, pump, and/or burner when an interior set point is reached.

In one embodiment, the gas control valve can be set between a high setting (HI) and a low setting (HI). Alternatively, the gas control valve can be variable. The gas control valve can be normally set on HI until the water in the radiator tank is within the minimum tank water temperature and the threshold temperature, such as between 140-160 degrees F., or above the threshold temperature, at which time the gas control valve can switch to LO.

In one example, when the blower is activated by the RTS, the power to the blower is applied to this connection and reduces the output of gas to the lower BTU rating. That is, the gas control valve is on LO. The burner can also be activated by the RTS when the RTS is not powered “ON” and the water temperature in the radiator tank falls below the minimum tank water temperature, such as, in one example, 140 degrees F. Thus, when water is to be heated or air is to be heated, but not both, the gas control valve can operate on LO. When both water and space are to be heated simultaneously, the gas control valve can be on HI. In an example, the LO setting can be about 12K to about 18K BTU, and the HI setting can be about 35K to about 37K BTU. A relay (R) can prevent the gas control valve from switching to LO if both the water heating and space heating are used simultaneously. The pump can be operating continuously while the burner is on.

Within the core body of the heater core, a plurality of spaced apart fins are provided. The fins can be closely spaced or loosely spaced inside the core body to form baffles or channels for the flow of return air from the radiator compartment through the heater core generated by the suction of the blower. The number of fins can depend on the desired heat exchange rate by convection, conduction, and radiation exchanging with the interior run line of the heater core tubing. The heater core tubing passes through the fins and wherein U-shaped returns are provided on opposite exterior surfaces of the heater core body to connect the parallel tubing sections in a serpentine fashion within the interior space of the heater core. The number of fins and the total tubing length passing inside the heater core can be selected to control the residual time of water travelling through the heater core and the amount of heat transferring directly from the heater core tubing to the fins and then to the return air. In one embodiment, the heater core tubing and the fins are made from a highly conductive material, such as copper, brass, or their alloys.

A pneumatic resistance screen can be provided inside the heater core between the fins and the front opening to increase the efficiency of the heater core. The pneumatic resistance screen can reduce the velocity of the return air pulled into the suction port of the blower to increase the resistance and therefore heat transfer from the heater core tubing and the fins to the return air as it passes through the fins into the blower.

A three-way tee can bifurcate the line from the heater core to direct the heated water to the mixing valve and back to the radiator tank through the one-way valve and the hot water return line. In one example, if hot water is not being used, such as not exiting the water outlet, then the water will circulate back into the radiator tank. If some hot water is used, then only the remaining portion of hot water not leaving the hydro-furnace will be returned to the tank. As hot water leaves the hydro-furnace, water from the water supply can flow into the water inlet to replace the heated water leaving the hydro-furnace. Thus, the amount of water held in the hydro-furnace can remain relatively constant.

The ignition control box, which can house the DSI board, can comprise a control box base and a cover. The cover can be flush with the surface of the housing or extend partially out from the housing surface. Alternatively, the cover can remain inside the housing. In one embodiment, the electro-mechanical control system is similar to those found in standard furnaces and water heaters. The DSI board is a microprocessor based control board that operates all functions of the hydro-furnace and provides terminal connections for power, such as +12V, grounding, the gas control valve to open and shut off the gas to the burner, ignition terminal for the spark igniter to light the burner, a remote indicator (LGT) to provide feedback on the hydro-furnace operation and possible faults, and a safety loop to verify that the TECO and BECO are not open. The LGT can provide feedback and alerts in the form of LEDs located on the cover of the ignition control box, a surface of the housing, or a control panel located away from the housing. Optionally, an audible alarm may be incorporated to provide alerts.

A DSI board provided herein can be a microprocessor based control board that can operate all the function of the hydro-furnace according to safety and regulation standards and provide connections and controls for a sufficiently voltage for activating the ignition to the burner, a ground connection, the control of the gas valve to open, shut off, and the control of gas flowing to the burner, remote indicate (LED) power to provide feedback on operation of the hydro-furnace and possible faults, and safety loop to verify that the TECO and BECO thermostats are not open, among others.

The power terminal of the DSI board can be connected to a DC power supply source, such as the battery power supply source of the RV via a power cable. The grounding terminal can be connected to a grounding cable to the RV to ground the circuit. The DSI board and the microprocessor in the DSI board of the hydro-furnace can accept different voltages, such as 12 Volt DC to 24 Volt DC. Generally, 12 Volt DC can be produced by the on-board power system of the RV to power various auxiliary devices. The power can be tied or linked to the ignition system or supplied from a battery bank with fulltime power, as is well known in the RV industry. The battery bank that supplies fulltime power can be charged by the vehicle's generator or by plug-in AC power when the RV is plugged into an AC source.

In addition to the DC connector port discussed above, an I/O connector port can be used to set control parameters for the controller. Like the DC connector port, the I/O connector port can be a passage or bore through the housing having a plastic ferrule or liner that allows one or more cables to pass therethrough for connections between the electric system of the water heater, such as the microprocessor, and a control panel, which can be mounted remotely rom the hydro-furnace, such as near the kitchen, bathroom, or the vehicle dashboard. Power may be supplied to the thermostats and sensors, such as the TECO, BECO, LTS, and HTS, through the DSI board or separately from the DC power source of the RV.

The ignition terminal can be provided for the ignitor high voltage wires, which supply the necessary power to ignition control electronics including the ignition control spark to supply the ignition source for the burner.

The RTS can be connected to the DC power supply source, the relay (R), the blower, the thermostats and temperature sensors, and the pump.

Various functions of the hydro-furnace, such as set temperature, water flow rate, and air flow rate, may be controlled by the DSI board. The microprocessor in the DSI board can act as a gateway for receiving signals and data from the various sensors and is programmed to control operation of various components of the hydro-furnace based on the received signals and data, as further discussed below. For example, based on the temperature data received from one of the thermostats or probes, the microprocessor can send control signals to the gas control valve to modulate gas flow feeding the burner.

The controller or DSI board of the hydro-furnace can be connected to an onboard fulltime DC power supply of the RV and not dependent on the car ignition system. By connecting to the vehicle's fulltime power, the DSI board is always powered and various set points using a control panel and various parameters and data used by the microprocessor can be maintained or saved. In other examples, the DSI board is equipped with auxiliary memory that stores set points and parameters and can retain the information even when power is disconnected to the DSI board. When auxiliary memory is incorporated, the DSI board can be supplied with the vehicle's generator power.

The electronic control system can be similar to an electro-mechanical control system, except that an electronic control board is used to monitor the water temperature using thermistors instead of thermostats. In an example, the LTS and HTS of the electro-mechanical control system are respectively replaced by the thermistor probes Tin and Tout of the electronic control system. The Tin probe can be placed at the input of the heat exchanger and the thermistor probe Tout can be placed at the output of the heat exchanger downstream of the BECO. The electronic control system can further include a thermistor probe T1 located at the top of the radiator tank and a thermistor probe T2 located at the bottom of the radiator tank to determine the state of mixing of the water and, indirectly, the water heating function. In another example, the T1 probe can be located at the upstream end of the radiator tank and the T2 probe can be located at the downstream end of the radiator tank. The electronic control board can directly activate the pump and the blower based on precise values measured by thermistor probes T1, T2, Tin, Tout, which can be directly connected to the electronic control board.

The DSI board in the electronic control system is also similar to the electromechanical control system, except that the power terminal is now connected to the electronic control board instead of the thermostats and temperature sensors. The RTS can also be connected directly to the electronic control board. Thus, operations in the electronic control system can be handled by the electronic control board. More precisely, a microprocessor in the electronic control board can receive and send signals to power and control the components in the hydro-furnace.

In the present embodiment, the heated water can be stored in a coil reservoir instead of a radiator tank. The coil reservoir can be a tubular structure that can extend between opposite sides of the radiator compartment in a serpentine fashion with U-shaped ends connecting parallel tubing sections extending in opposite directions within the interior space of the plenum. The coil reservoir can form a plurality of loops confined within the lower radiator chamber of the radiator compartment. Each of the plurality of loops can be spaced apart from each other to allow return air to be drawn outside the hydro-furnace from the lower return air vent through each of the loops or tubing sections. Return air in the Heat can be transferred from the coil reservoir into the return air inside the radiator compartment or lower radiator chamber before being drawn through the heater core into the blower. Thus, like the radiator tank, the coil reservoir can pre-heat the return air to improve heating efficiency of the hydro-furnace.

In still other examples, additional probes and/or sensors can be connected in-line with the various tubing and lines of the hydro-furnace in either system for sensing and controlling or regulating other flow functions in either the electro-mechanical system or the electronic control system. Other sensors such as pressure and flow sensors may be added for more advanced functions to improve performance, such as user selection of performance parameters, troubleshoot capabilities to identify various system failures, warnings to the user of potential failures, and remote control of all features from a panel or handheld unit or via internet access. The various connections can be threaded, welded, by mating flanges, or combinations thereof. In some examples, a threaded bore is provided on a side of a fitting, such as a threaded socket or a threaded thermowell, for receiving a probe, which can include a thermostat, a flow sensor, or other sensing devices. Optionally, welding may be used to connect the various components and tubing sections.

As available space can be limited in RVs, the present disclosure provides for modularization of the components of the hydro-furnace system. For example, the system can be generally separated into segmented sub-systems that can be stored or mounted in spaced apart configurations. In an example, the hydro-furnace system can be separated into a water heater module, a tank module, and a hydro-furnace module. The modules can be located separately from one another, such as spaced from one another in different segmented structures, throughout the RV, with necessary connections between them. In this way, the components of the hydro-furnace system can be installed in small spaces in the RV that already exist and are relatively easier to access without the need for designing a sufficiently large space for a single unit system. Additionally, the modularization can allow for modular sizing of components to fit the needs of the specific RV. For example, a larger RV may require a large storage tank or blower. In some examples, the hydro-furnace system can be separated into two or more sub-systems that can be mounted in spaced apart configurations.

The separation of the components can provide a benefit for better isolation of the water heater unit and the exhaust system, which can produce emissions byproducts from the burner that can be harmful if introduced into the interior of the RV. The other benefit, as previously described, is the flexibility of storing sub-components or sub-systems in multiple smaller spaces throughout the RV instead of a single large space.

The hydro-furnace system can have a water heater module that contains a water heater or water boiler. The water heater can be controlled by an electronic control board acting in response to a thermostat that monitors the water temperature using thermistor probes. The electronic control system can use a DSI board to control the water heater.

The room thermostat can generate a heat request for space heating as desired by a user. The electronic control board can receive the heat request from the room thermostat and control the components of the hydro-furnace system as necessary to provide the requested heat.

The electronic control board, though the DSI board, can control a burner in the water heater module. The water heater module can receive water from a cold water source or from the storage tank. In an initial state, the system is primed with water from the cold water source.

The water input into the water heater module can be heated and then either supplied as warm water through a warm water line to the user or as heated water through the hydro-furnace water circuit to provide heat to the RV.

From the water heater module, the heated water can flow through the hydro-furnace water circuit to the hydro-furnace module. There, the heated water can flow through a heat exchanger. A blower can move air across the heat exchanger to heat the air from heat transferred from the heated water. The blower can be controlled by the electronic control board. The heated air can then be distributed to the interior of the RV through the air vents of the hydro-furnace module. To improve the efficiency of the hydro-furnace module, there can be provided a pneumatic resistance screen in front of the heat exchanger. This can increase the efficiency of the heat exchanger by increasing the residual contact time with the heat exchanger, such as by reducing the velocity of the air being moved by the blower.

After circulating through the heat exchanger of the hydro-furnace module, the heated water flows to the tank module. There, the heated water flows through a one-way valve before flowing into the tank through a manifold. Water from the tank can then be recirculated to the water heater module through a downstream one-way valve by way of a pump and a solenoid valve. The pump can actively circulate the water through the water heater module until the temperature of the storage tank reaches a desired temperature. The temperature can be checked by way of a temperature probe downstream of the storage tank. The electronic control board can control the pump, solenoid valve, and blower based upon the readings from the thermostat and the temperature probe.

The use of the one-way valves, prevent mixing of water in the different phases of the heating loop. Upon the water of the storage tank reaching the desired temperature, the electronic control board can shut off the burner of the water heater module.

As scalding is based on both temperature and duration of contact, the present disclosure provides for a mechanism to prevent the risk of scalding to the user. The water heater module can be designed to provide a predetermined amount of maximum heating to the water. In this way, the maximum temperature of water heated from the cold water source can be limited to prevent scalding of a user when delivered for use through the water outlet.

To increase the heat of the water of the heating loop of the hydro-furnace system, the water from the heating loop can be continually cycled to water heater module and heated. In this way, the water can be heated to a higher temperature than that of the water delivered to the user.

Additionally, the heated water of the hydro-furnace system can be cut-off to the user by means of both the pump and the solenoid valve. Use of the solenoid valve allows for quick shut off of the flow of water from the stored water from flowing to the water heater. In this way, stored water that is hot is prevented from flowing into the water heater and being output to the customer. As a result of the shut off of flow from the stored water, the temperature of the water input into the water heater is limited by the inflow of cold water. The resulting heating of the water by the water heater is thereby limited in terms of the temperature of the water that can output to the user through the water outlet.

Furthermore an emergency cutoff (ECO) can be applied to the water outlet for preventing the temperature of the water for a user from being improperly high even in the case of a malfunction.

In addition to the singular hydro-furnace module, there can be additional hydro-furnace modules installed in the RV to provide zone specific heating as desired.

Embodiments of the water heater utilize a gas burner. However, it can also be envisioned that an electric water heater can also be used, which uses resistance heating coils or ceramic heating coils.

Additionally, the hydro-furnace system can use alternative control systems, such as electro-mechanical.

The water heater module incorporates a burner configured to heat water. The water heater module has a water input for receiving cold water or circulating water from the hydro-furnace heating loop. The water input may include a manual water shut off valve. The water input may be on a first side of the housing.

A fuel or gas inlet for introducing fuel to the burner in the water heater module can extend out from the first side of the housing. A fuel or gas line can be connected to the gas inlet to supply fuel, such as propane, to the burner. The gas inlet can be a male connector, however, the gas inlet may be a female connector extending into the housing, in which case a gas line having a male connector tip can engage the female connector to supply fuel to the burner. Pressure fittings may also be used to connect the various lines and components of the hydro-furnace system.

The water input can be coupled to a heat exchanger tubing as further illustrated. The heat exchanger tubing can wrap around the exterior of a heat exchanger, which can be a conductive body having a skirt or a plenum. The plenum and the heat exchanger tubing can be made of a conductive material, such as aluminum, copper, copper alloy, brass, alloys, or other metals.

The plenum and the heat exchanger tubing can be made from other corrosive resistant materials that are able to withstand the direct or indirect heat of the burner, or be plated or coated with a corrosive resistant material. The heat exchanger tubing can wrap around the plenum from a bottom end of the plenum towards a top end of the plenum, elevation-wise, and by conduction is heated by the plenum which then heats the water running through the heat exchanger tubing. This can be understood as being similar to a preheat. Because both the plenum and the heat exchanger tubing can be made from a conductive material, heat energy is transferred by conduction from the plenum to the heat exchanger tubing and from the heat exchanger tubing to the water running therein. As a result, the water running around the heat exchanger is pre-heated before entering the heat exchanger. The heat exchanger tubing then enters the heat exchanger so as to be heated by the heated gas from the burner, as further discussed below.

The plenum can have an opening extending from the bottom end to the top end. Within the plenum of the heat exchanger, a plurality of spaced apart internal fins can be located in the opening between the bottom end and the top end to provide additional heat transfer paths. In one example, the internal fins are located near the top end to provide space for the burner. The internal fins can be closely spaced or loosely spaced inside the plenum to form baffles or channels for the flow of heated air from the bottom end of the heat exchanger and then rising through the internal fins and out the top of the heat exchanger, elevation-wise.

The number of internal fins and the surface area of each of the internal fins can depend on the desired heat exchange rate by convection, conduction, and radiation exchanging with the interior run line of the heat exchanger tubing. The heat exchanger tubing passes through the internal fins and wherein U-shaped returns are provided on outer surfaces on opposite sides of the plenum to connect the parallel tubing sections in a serpentine fashion within the interior space of the plenum. Thus, the heating pipe can form continuous passes through the opposite sides of the plenum and the internal fins to maximize the heat transfer from the internal fins to the heat exchanger tubing to heat the water flowing therein. The number of fins and the total tubing length passing inside the plenum can be selected to control the residual time of water travelling through the plenum and the amount of heat transferring directly from the burner to the plenum and from the burner to the fins and then to the heat exchanger tubing.

The water heated through the heat exchanger tubing can then output through water output for delivery to the user or the hydro-furnace heating loop.

An electrical connector can be provided on the first side of the house also for connection of the electronics housed in the water heater module. The electrical connector may be a quick disconnect type. The electrical connector may be a plurality of connectors for different power and signal connections.

An exhaust system comprising an exhaust conduit or duct can be provided to collect exhaust fumes rising from the burner and direct the exhaust fumes and away from and outside the water heater module through the burner outlet vent. The exhaust system can be positioned at the top of the plenum and coupled directly to the top end of the plenum. The exhaust system can extend horizontally towards the burner outlet vent. The exhaust system can have a larger opening at the output end to provide an open flow path to the burner outlet vent for the combustion byproducts.

The exhaust system can be sealed to ensure the combustion byproducts flow directly out the burner outlet vent. An exhaust fan powered by an exhaust fan motor may also be provided to assist directing the exhaust fumes through the burner outlet vent. The exhaust fan may be connected to a microprocessor of a controller such as the DSI board explained. The DSI board can operate the exhaust fan motor to turn the exhaust fan on and off based on signals sent to the microprocessor from one or more sensors.

Additional ducting may be provided to direct the exhaust gas through the burner outlet vent and out, such as out an opening to an exterior of the mobile or recreational vehicle. In some examples, an induced draft fan, a force draft fan, or both can be incorporated to move gas through the hydro-furnace.

Embodiments of the tank module can have a water storage tank, an upstream one way valve, a downstream one way valve, a pump, and a solenoid valve. The tank module can contain only some of the components of the storage tank, the upstream one way valve, the downstream one way valve, the pump, and the solenoid valve. It is possible to place the upstream one way valve, the downstream one way valve, the pump, and the solenoid valve in locations along the system between the water heater module, the tank module, and the hydro-furnace module.

The storage tank can store hot water for the hydro-furnace water circuit. The storage tank can be an expansion tank and contain a resilient bladder certified for the operating temperature and pressure. The expansion tank can protect the RV water system from excessive pressure. The tank can be partially filled with air, the compressibility of which absorbs excess water pressure and/or water volume.

The storage tank may be cylindrical in shape. The storage tank may be oriented in an upright position, with an opening at one of the end surfaces of the cylindrical shape, the end surface considered the downward oriented face when installed in an RV.

The storage tank can have an alternative shape, such as rectangular, trapezoidal, or spherical. Also, the storage tank can be oriented in different directions, such as having the cylindrical shape be oriented on its side.

The opening of the storage tank is coupled to a manifold. The manifold can include an input side connected to a tube. The tube can convey the water from the input side to an upper portion of the storage tank. The manifold can allow for water to exit the storage tank at the bottom of the storage tank at the opening. In this way, the tank can have heated water conveyed to the top portion while relatively cooler, denser water at the bottom of the storage tank can be drawn.

The manifold can include a chamber area for the output side. The chamber area can connect to the downstream section of the piping of the system.

The manifold can be coupled to the storage tank by way of corresponding threading. The coupling can also be achieved by way of corresponding lugs and grooves on the components. The coupling can also be achieved by way of a slip fit, and can also utilize a clamping ring over the slip fit.

The manifold can be on the bottom surface of the storage tank. However, the manifold could be attached to side surfaces of the storage tank instead of the bottom surface. The manifold can be attached to a lower portion of a side surface near the bottom portion of the storage tank.

The manifold can be a single connection point for both the input side and outside side. Additionally, the manifold can also be achieved with two connection points. The input side can be separated from the output side. Instead of a single connection point, the input side can be attached to a second opening of the storage tank. In such a case, the opening for the input side can be provided where convenient. The input side in such a case can utilize a tube as necessary to convey water to the upper portion of the storage tank.

Alternatively, the opening may be provided at an upper portion of the storage tank, such that a tube is not necessary. Combinations of such a split connection could have the input side and the output side located on different surfaces of the storage tank.

The connections to the storage tank can be arranged as necessary to fit the installation layout of the RV. An installation can have the routing of pipe connecting the components resulting in a U-shape underneath the storage tank to minimize a footprint of the components for compactness. In this case, the upstream one way valve can be in line with the manifold. The routing can then go through a 90 degree bend to the downstream one-way valve. After the downstream one-way valve, the routing can then go through another 90 degree bend to the pump and the solenoid valve. Alterative bend configurations may be used as necessary to provide the convenient routing and attachment to the tank module when installed in the RV.

The upstream one way valve, by only allowing flow in a direction from the hydro-furnace module to the tank module, prevents the potential mixing of water stored in the tank back to the water used for heating with the hydro-furnace module.

Downstream of the manifold, there is the downstream one way valve coupled in line with the pump, and the solenoid valve. The downstream one way valve can prevent flow of water back into the storage tank and mixing from downstream. The pump can be powered to pump water from the storage tank back to the water heater module.

To minimize the risk of hot water being released, the solenoid valve can be used to control the flow of water from tank module back to the water heater module. The solenoid valve can be used to provide a quick shut off mechanism to prevent flow of hot water stored in the storage tank. For safety, the solenoid valve can be of a type that is closed, or prevents flow, in an unpowered state, or off state. In this way, if there is a power loss to the solenoid valve, the hydro-furnace water circuit is cut-off from providing hot water back to the water heater module.

The tank module can have a housing to house the components of the tank module. The housing may house just the tank. The housing may house some or all of the storage tank, the upstream one way valve, the downstream one way valve, the pump, and the solenoid valve. The housing can be shaped to substantially correspond to the storage tank. The housing can be shaped to correspond to a space in the RV or mobile vehicle. The components of the tank module can be retained inside the housing by being sized to fit or by retention methods such as mounting brackets. It is not necessary that each and every component be retained, but only that sufficient constraining is provided to minimize excess force from acting on the components. The use of a housing can allow for fitment inside the RV while using off-the-shelf components, which may be sized or shaped differently. For example, the expansion tank can be an off-the-shelf item that can be easily procured for different installation types. In this way, the mere change in dimensions for the house is much simpler and cheaper than attempting to custom design storage tanks for different installations.

The hydro-furnace module can include a blower, a heat exchanger, and a pneumatic resistance screen. Other components or elements may be included with the hydro-furnace module, such as fittings, brackets, sensors, etc.

The hydro-furnace module can further include a housing to house the components of the hydro-furnace module. The housing can provide air vents to route the heated air into the interior of the RV. The hydro-furnace module can receive heated water from the water heater module and route the heated water through the heat exchanger. The heat exchanger transfers heat from the water to the air of the hydro-furnace module, such that heated return air can be supplied by the blower. The heat exchanger can comprise a core body with a box-like shape and core tubing.

In embodiments, the blower can have a suction portion and a blower port to move the air. Alternatively, the ports can be reversed, or a different type of blower can be used, as desired.

Within the core body of the heat exchanger, a plurality of spaced apart fins can be provided. The fins can be closely spaced or loosely spaced inside the core body to form baffles or channels for the flow of air through the heat exchanger generated by the moving of air by the blower. The number of fins can depend on the desired heat exchange rate by convection, conduction, and radiation exchanging with the interior run line of the core tubing.

The core tubing passes through the fins and wherein U-shaped returns are provided on opposite exterior surfaces of the core body to connect the parallel tubing sections in a serpentine fashion within the interior space of the heat exchanger. The number of fins and the total tubing length passing inside the heat exchanger can be selected to control the residual time of water travelling through the heat exchanger and the amount of heat transferring directly from the core tubing to the fins and then to the air.

In one embodiment, the core tubing and the fins, are made from a highly conductive material, such as copper, brass, or their alloys.

In this way, the blower can move air over the heat exchanger to transfer the heat from the water to the air of the hydro-furnace module. The heated air can then be provided through air vents from the housing of the hydro-furnace module to the interior of the RV. The air vents can be provided to the housing such that there is necessarily some circulation of heated air inside the housing of the hydro-furnace module as the blower operates. As such, the temperature of the air inside the house can be higher than ambient.

The present disclosure provides a modular RV water heating and furnace system having a heat exchanger housing that houses a heat exchanger and a burner, a hydro-furnace housing that houses a heater core and a blower, and a tank housing that houses a storage tank.

The burner provides heat to the heat exchanger and the heat exchanger heats water flowing therethrough it.

The blower moves air through the heater core, which is provided with the heated water from the heat exchanger.

The present disclosure provides a modular RV water heating and furnace system having a water heater, a heat exchanger, and a storage tank. The water heater heats input water and outputs the heated water. The heated water is then provided to the heat exchanger. The heat exchanger attached to a blower, which moves air through the heat exchanger, thereby warming the air. The heated water is then provided through a one-way valve from the heat exchanger to a storage tank. The heated water is then provided from a second one-way valve to a pump and a solenoid valve for circulation back to the water heater.

Methods of making the hydro-furnace systems, of using the hydro-furnace systems, and of installing the hydro-furnace systems as described herein are within the scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the present devices, systems, and methods will become appreciated as the same becomes better understood with reference to the specification, claims and appended drawings wherein:

FIG. 1 shows a perspective view of an embodiment of a combination water and air heating system for an RV;

FIG. 2 shows an exploded perspective view of the combination water and air heating system of FIG. 1;

FIG. 3 shows a perspective view of the combination water and air heating system of FIG. 1 shown without panels to expose the various internal components of the water heater;

FIG. 4 shows a perspective view of the combination water and air heating system of FIG. 3, but shown from a different aspect;

FIG. 5 shows a perspective view of the combination water and air heating system of FIG. 3, but shown from another different aspect;

FIGS. 6A and 6B show a front view and a bottom view of the combination water and air heating system of FIG. 1;

FIG. 7 shows a schematic diagram of the combination water and air heating system of FIG. 1, illustrating one embodiment of the principles of operation.

FIG. 8 shows a schematic diagram of one embodiment of the combination water and air heating system utilizing an electromechanical control system;

FIG. 9 shows a schematic diagram of one embodiment of the combination water and air heating system utilizing an electronic control system; and

FIG. 10 shows a perspective view of another embodiment of a combination water and air heating system for an RV with a coil reservoir tank.

FIG. 11 shows a schematic layout for a modularized hydro-furnace system 100 using an electronic control system.

FIG. 12 shows a side view of exemplary implementations of the different sub-systems of FIG. 11.

FIG. 13 shows a perspective view of exemplary implementations of the different sub-systems of FIG. 11.

FIG. 14 shows a perspective view of an arrangement of a tank module with a storage tank and flow control components.

FIG. 15 shows a perspective view of an arrangement of a blower and heat exchanger for providing heated air to an RV.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appended drawings is intended as a description of the presently preferred embodiments of a combination water and air heating system for a recreational vehicle (RV) provided in accordance with aspects of the present assemblies, systems, and methods and is not intended to represent the only forms in which the present devices, systems, and methods may be constructed or utilized. The description sets forth the features and the steps for constructing and using embodiments of the present assemblies, systems, and methods in connection with the illustrated embodiments. It is to be understood, however, that the same or equivalent functions and structures may be accomplished by different embodiments that are also intended to be encompassed within the scope of the present disclosure. As denoted elsewhere herein, like element numbers are intended to indicate like or similar elements or features.

With reference now to FIG. 1, a perspective view of a combination water and air heating system or “hydro-furnace” 100 for a mobile vehicle, which can include a recreational vehicle (RV), a boat, a mobile home trailer or fifth wheel, provided in accordance with aspects of the present disclosure is shown. The hydro-furnace 100 can function as both a water heater and a space heater by supplying both hot water and hot air through three basic systems: a boiler system, a recirculating system, and a radiator system. Heated water and heated air can be generated concurrently or serially. Generally speaking, the boiler system can provide a heat source for water running therethrough by combusting air and fuel, such as propane, and exhausting combustion products to provide on-demand hot water and hot water for a storage tank.

Because fuel and byproducts of fuel are involved, the boiler system can be sealed off from the recirculating system and the radiator system to prevent combustion byproducts and unused fuel from entering the RV and potentially circulating harmful gas throughout the mobile vehicle. For purposes of the following disclosure, reference is made to an RV although other mobile vehicles can use the hydro-furnace of the present disclosure.

To increase the temperature inside the RV, the recirculating system can heat return air drawn from inside the RV using the water heated in the boiler system as the heat source, and deliver the heated air back inside the RV. The radiator system can store heated water and heat the return air when hot air is desired. As described in further detail below, the boiler system can include gas and electrical controls, a burner, a heat exchanger, a water pump, water tubing and connections, and an exhaust system. The recirculating system can include a blower, a heater core, a return air port, and water tubing and connections. The radiator system can include a radiator tank, an air plenum and duct ports, and water tubing and connections. However, components of the three systems can be re-arranged within the housing of the hydro-furnace without deviating from the scope of the invention.

Each of the three systems can be contained within one or more chambers or compartments within a housing 102. The components contained in the housing 102 can include gas lines, water lines, sensors, switches, mechanical and electromechanical components, and electronics for controlling the flow and operation of both the fuel and water flowing into and/or through the hydro-furnace 100. Note that a hydro-furnace for an RV, such as the hydro-furnace 100 disclosed herein, is different from a portable water heater and a portable room heater, which is understood to be portable but not necessarily for the heavy duty use and more rigid requirements for RVs.

The housing 102 can comprise a plurality of removable panels mounted together to form two or more sides of the hydro-furnace 100 and enclose the various components inside the hydro-furnace 100. Any number of panels and sub-panels can be included to form the outer surface of the hydro-furnace 100 and divide an interior of the housing 102 into separate smaller housings or compartments to house components of each of the three systems. In some examples, one or more of the panels of the housing can be permanent or non-removable from a housing frame.

In the illustrated embodiment, the housing 102 can be divided into a radiator compartment 102 a at a back side or second side 101 b of the hydro-furnace 100 and a main compartment 80 at a front side or first side 101 a of the hydro-furnace 100. The main compartment 80 can be further divided into a blower compartment 102 b and a burner compartment 102 c. As shown, the burner compartment 102 is located on a left side 101 c of the hydro-furnace 100, from the perspective of the first side 101 a looking at the second side 101 b and the blower compartment 102 b is located on a right side 101 d of the hydro-furnace 100.

In another embodiment, the burner compartment 102 is located on the right side 101 d of the hydro-furnace 100 and the blower compartment 102 b is located on a left side 101 c of the hydro-furnace 100. Said differently, the burner compartment 102 c and the blower compartment 102 b can be located along a first side or a front side 101 a of the housing 102, and the radiator compartment 102 a can be located along a second side or a back side 101 b of the housing 102 directly opposite the first side. The components of the radiator system, the recirculating system, and the burner system can cooperate by extending through the interior sections of the housing 102, better illustrated in reference to FIG. 2.

For purposes of the following discussions, the first side or front side 101 a of the housing 102 shown in FIG. 1 can also be considered the front of the hydro-furnace 100, and the second side or back side 101 b of the housing 102 can be considered the back of the hydro-furnace 100. One of ordinary skill in the art will recognize that these directional assignments to the components of the housing 102 and the hydro-furnace 100 are for purposes of description only as the hydro-furnace 100 may be installed in any orientation that allows for proper operation.

The housing 102 includes vents, input and output connectors, and interface ports for connecting the hydro-furnace 100 to the RV. A burner inlet vent 103 for introducing air outside of the housing 102 into the burner compartment 102 c is shown located at the front side of the housing 102. A burner outlet vent 105 for channeling combustion byproducts of a burner 275 for heating a heat exchanger 250, unburned fuel, and other gases outside the burner compartment 102 c is shown located above the burner inlet vent 103 at the front side of the housing 102. Thus, the burner inlet vent 103 and the burner outlet vent 105 are provided on a front side of the hydro-furnace 100. The burner compartment 102 c can be sealed off from the other compartments to prevent the combustion byproducts of the burner 275, unburned fuel, and other gases inside the burner compartment 102 c from entering the blower compartment 102 b and the radiator compartment 102 a of the housing 102 and mixing with the heated air to be delivered inside the RV. For example, ducting can be connected to the burner outlet vent 105 to direct the exhaust gas to the exterior of the RV.

A fuel or gas inlet 104 (FIG. 4) for introducing fuel to the burner 275 in the burner compartment 102 c is shown extending out from a third side or left side of the housing 102. Alternatively, the gas inlet 104 can be located on a front side of the housing 102. In another embodiment, the gas inlet 104 is located on a right side of the housing 102, depending on the location of the burner compartment 102 c within the housing 102. Again, the orientation of the various components relative to the housing is not crucial and can vary without deviating from the scope of the present invention.

A fuel or gas line can be connected to the gas inlet 104 to supply fuel, such as propane, to the burner 275. As shown, the gas inlet 104 is a male connector but a female connector can optionally be used, in which case a gas line having a male connector tip can engage the female connector to supply fuel to the hydro-furnace 100. A gas tubing or line can be provided to connect the gas inlet 104 to a gas control valve 278, which can be connected in line to a burner 275 to control gas flow from a gas source through the burner of the hydro-furnace 100. Other valves, such as linear or equal percentage valves, are contemplated for use with the present system to regulate gas flow through the hydro-furnace.

Control of the gas control valve 278 can be based on various sensed parameters, such as water flow, inlet and/or outlet water temperatures, and set point. In one embodiment, the gas control valve 278 is a linear valve. In an example, the linear valve is provided by CAE, model number CPV-H2467AY, which can be used to control gas flow through the hydro-furnace 100. An additional valve in line with the gas control valve 278 may be used to further control gas flow, function as an emergency shut off valve, or any desired function. The additional valve can be an on/off solenoid valve that can function as an emergency shut off valve and that can receive operating signals from an emergency cut off switch (ECO), which can be a bi-metallic switch.

The gas control valve 278 can be connected to a microprocessor of a controller, which can be programmed to control the gas control valve 278 based on data and signals received from sensors such as thermostats or thermistor probes. In general, the gas control valve 278 can be an on/off valve with a high/low setting. Alternatively, an additional valve can be an on/off valve and the gas control valve 278 can be regulated to control gas flow from a high setting to a low setting, as described in further detail below. Together, the gas control valve 278 and the additional valve may also act as a dual emergency shut off valve when both are in the off position. In one example, the hydro-furnace 100 may accept propane gas only, such as while travelling with propane tanks or when parked at a camp site. In another example, the hydro-furnace 100 may accept another type of fuel that can be supplied through the gas inlet valve 104, such as a gas source at a camp site.

A DC connector port for powering the hydro-furnace 100 can be located adjacent the gas inlet valve 104. In an example, the DC connector port is a passage or bore through the housing 102 having a plastic ferrule or liner that allows one or more cables to pass therethrough for connections between the electric system of the hydro-furnace 100, including the controller or DSI board inside or adjacent to an ignition control box 280 discussed in detail below, and the vehicle's electric system.

A water inlet 106 (FIG. 3) for introducing water from a water supply into the radiator compartment 102 a is shown extending out from a fourth side or right side 101 d of the housing 102 opposite the left side 101 c of the housing 102. Alternatively, the water inlet 106 can be installed extending from the same side but from the blower compartment 102 b. A water outlet 108 for delivering heated water out from the hydro-furnace 100 is also shown extending out from the fourth side or right side 101 d of the housing 102 adjacent to the water inlet 106. The water inlet 106 and the water outlet 108 can be mounted side-by-side or one above another elevation-wise. The location of the water inlet 106 and the water outlet 108 is not limited, and can also be located on other sides of the housing 102 or separately on different sides of the housing 102.

A voltage connector port for powering the hydro-furnace 100 can be located adjacent the gas control valve 278 or at some other accessible location within the housing 102. In an example, the voltage connector port can be a DC connector port. The DC connector port can be a passage or bore extending through the housing having a plastic ferrule or plastic liner that allows one or more cables to pass therethrough for connections between the electric system of the water heater, such as the controller, and the vehicle's electric system. The voltage connector port may also be sealed air-tight to prevent gases in the burner chamber 102 c from leaking out other than the burner outlet vent 105.

A first or upper return air vent 107 (FIGS. 1 and 2) and a second or lower return air vent 109 can extend through the second or back side 101 b of the housing 102 to allow return air outside the housing 102 to be pulled into the blower compartment 102 b of the hydro-furnace 100 through the radiator compartment 102 a. A heater core 300 located in the blower compartment 102 c by a blower 325 is provided for heating the return air. A filter, such as a HEPA filter or other high efficiency filters, can be provided at the upper return air vent 107, the lower return air vent 109, or both vents 107, 109, so that the return air can be filtered before it is heated and delivered. This can also ensure cleanliness of the components in the system. The filter can be installed inside or outside of the housing 102. If installed outside the housing 102, the filter can be easily attached and detached easily from the hydro-furnace 100 for cleaning or replacement, such as in a cartridge compartment attached to the housing.

FIG. 2 shows an exploded view of the housing 102 of the hydro-furnace 100 to better illustrate how the components can be assembled inside the compartments formed by the panels of the housing 102. The radiator compartment 102 a can be rectangular shaped and formed from a C-shaped radiator housing panel 110 having a central panel and two subpanels extending from opposite edges of the central panel. A left side radiator housing panel 112 and a right side radiator housing panel 114 can attach to the ends of the central panel and the two subpanels of the C-shaped radiator housing panel 110. A radiator housing door 116, which comprises air vents 107, 109, can attach to the remaining free ends of the two subpanels of the C-shaped radiator housing panel 110 to cover the opening opposite the central panel of the C-shaped radiator housing panel 110.

The upper return air vent 107 and the lower return air vent 109 are located on the radiator housing door 116. Thus, the radiator housing door 116 can also be the back side 101 b of the housing 102. An optional radiator housing divider 118 can be positioned inside the radiator compartment 102 a to subdivide the radiator compartment 102 a into separate smaller compartments. As shown in FIG. 1, the radiator housing divider 118 can extend from the central panel of the C-shaped radiator housing panel 110 to the radiator housing door 116 between the upper return air vent 107 and the lower return air vent 109 to divide the radiator compartment 102 a into an upper radiator chamber 111 and a lower radiator chamber 113. Thus, return air can be drawn into the upper radiator chamber 111 through the upper return air vent 107 and return air can be drawn into the lower radiator chamber 113 through the lower return air vent 109. The lower radiator chamber 113 can house a radiator tank 200 to preheat the return air as further discussed below.

Adjacent the radiator compartment 102 a is the main compartment 80, which can polygonal shape, such as a rectangular shape, and formed from a C-shaped main housing panel 120 having a central panel and two subpanels extending from opposite edges of the central panel. A left side main housing panel 122 and a right side main housing panel 124 covering the ends of the C-shaped main housing panel 120 or, more specifically, attached to the ends of the central panel to form an enclosure. The two subpanels of the C-shaped main housing panel 120 and a radiator housing door 116 are attached to the remaining free ends of the two subpanels of the main housing panel 120 to cover the opening of the C-shaped main housing panel 120 opposite the central panel of the C-shaped main housing panel 120.

A main housing divider 128 can be positioned inside the main compartment to subdivide the main compartment into the blower compartment 102 b and the burner compartment 102 c. As shown in FIG. 1, the main housing divider 128 can extend between the subpanels, the central panel of the C-shaped main housing panel 120, and the main housing door 126 to divide the main compartment into a left compartment or the burner compartment 102 c and a right compartment or the blower compartment 102 b.

The burner inlet vent 103 and the burner outlet vent 105 for providing ventilation for only the burner compartment 102 c can be located on the main housing door 126. Thus, the main housing door 116 can be the first or front side 102 a of the housing 102. The main housing divider 128 can be provided to effectively seal the burner compartment 102 c from the blower compartment 102 b to prevent fuel and combustion by products from entering into the blower compartment 102 b.

Air passages and water lines or tubing can extend between the radiator compartment 102 a, the adjacent blower compartment 102 b, and the adjacent burner compartment 102 c through one or more cutouts defined in both of the central panels of the C-shaped radiator housing panel 110, the C-shaped main housing panel 110, and the main housing divider 128. The various cutouts between the central panels and other internal panels allow the components, such as cables, wires, tubing, lines, fittings, brackets, electronics, fans, etc., from each system to connect to another system. Any cutouts between the burner compartment 102 c and any other compartment to allow components to extend therethrough can be sealed with components extending therethrough to prevent gases from leaking into the blower compartment 102 b or the radiator compartment 102 a. Optionally, sealants, fire retardant fabric or cloth, or other paneling means for isolating the different compartments can be used.

The cutouts between adjacent compartments can be similarly shaped and aligned to each other. In one example, an upper first cutout 111, a second cutout 113 below the upper first cutout 111, and a lower third cutout 115 below the second cutout 113 of the central panel of the C-shaped radiator housing panel 110 can align with similarly shaped cutouts on the main housing panel 120. In an example, the first cutout can be rectangular, the second cutout can be circular, and the third cutout can be rectangular. The cutouts on the main housing panel 120 therefore include an upper rectangular cutout or first cutout 121, a second cutout or a circular cutout 123 below the upper rectangular cutout 121, and a third cutout or a lower rectangular cutout 125 below the circular cutout 123 of the central panel of the C-shaped main housing panel 120. Alternatively, a single panel can divide the radiator compartment 102 a from the main compartment so that alignment of cutouts from different panels is not necessary. The function of each of the compartments of the housing 102 and how each relate to the other can be elaborated further with details of the components inside the housing 102 with reference to FIGS. 3-6.

Referring to the schematic flow diagram shown in FIG. 7, a general overview of the principles and operations of the hydro-furnace 100 is shown. When hot water and/or hot air is desired, the hydro-furnace 100 can be powered on to activate the electrical and electro-mechanical components of the system. If water is not already present in the hydro-furnace 100, water can be directed from a water supply (not shown) through the water inlet 106 into a radiator tank 200 located in the radiator compartment 102 a and to a mixing valve 150 located in the blower compartment 102 c. Water line pressure or from a pump can move the water through the system.

Initially, the temperature of the water in the radiator tank 200 may be at or near the temperature of the inlet water flowing through the water inlet 106. Eventually, the temperature of the water in the radiator tank 200 will increase as it circulates through the hydro-furnace 100, as discussed further below. The radiator tank 200 is configured to store the heated water and transfer heat from the stored heated water to the return air flowing past the radiator tank 200 when the blower 325 is on to heat the return air as discussed further below. The mixing valve 150 can regulate fluid flow between heated water leaving the heater core 300 and water from the water inlet 106. That is, the mixing valve 150 can mix the water at the two different temperatures from the two different sources to achieve a desired downstream or outlet water temperature of the water exiting the hot water outlet 108. Said differently, the mixing valve 150 can mix the water from the water inlet 106 with the heated water from the heater core 300 to provide hot water at the desired outlet water temperature.

In one example, the desired outlet water temperature of the hot water leaving the hydro-furnace 100 through the hot water outlet 108 can be 120 degrees F. Thus, the mixing valve 150 has two inputs and one output. The mixing valve 150 can be a manually operable control valve or an electronically adjustable control valve. The outlet water temperature can be adjusted by controlling the mixing valve 150. In one embodiment, a microprocessor of a controller can send signals to adjust the mixing valve 150 to produce a desired outlet water temperature using feedback from a temperature sensor located at or near the hot water outlet 108.

Before hot water can be dispensed from the hot water outlet 108, the water inside the radiator tank 200 can be heated to an acceptable temperature. To do so, the water can be circulated from the radiator tank 200 by a pump 170, to a heat exchanger 250 where the water is heated by a burner 275. The heat exchanger 250 can be heated directly or indirectly by a burner 275 located in the burner compartment 102 c. The burner 275 can burn fuel fed from the gas inlet 104 to produce combustion gases to heat the water in the heat exchanger 250. In one example, the fuel is liquefied petroleum (LP) gas or propane. The heat exchanger 250 can transfer heat from the combustion gases to the water.

From the heat exchanger 250, the water is pumped to a heater core 300. At least some of the heat from the heated water in the heater core 300 can be drawn or pulled by a blower 325 when powered on to provide heated air. The blower 325 can heat return air in the RV by pulling the return air past the radiator tank 200 and through the heater core 300 before delivering the heated air to an air plenum 340 (FIG. 7) and back to the RV through heating ducts 345. Return air drawn through the lower return vent 109 passing over the radiator tank 200 can also transfer heat by convection to the surrounding return air. More specifically, when a heat request is generated by a room thermostat (RTS) 360 (FIGS. 8 and 9) for space heating, the blower 325 can turn on to pull return air from the upper and lower radiator chambers of the radiator compartment 102 a through the heater core 300 to supply heated air to an air plenum 340 located in the radiator compartment 102 a or blower compartment 102 b.

The air plenum 340 is connected to heating ducts 345 extending outside the hydro-furnace 100. The air plenum 340 can accumulate the hot air from the heater core 300 at an elevated pressure to force and direct the hot air into the heating ducts 345, which lead air back inside the RV. In one example, the entire blower compartment 102 b can be the air plenum 340. Return air circulating in the lower radiator chamber 113 can be preheated from the radiator tank 200 to increase the efficiency of the system. When the blower 325 is activated to generate heated air, the heater core 300 can provide convective heat transfer from the heated water running through the tubing inside the heater core 300 to the return air drawn in from the upper radiator chamber and the lower radiator chamber until the desired room temperature is reached, at which time the RTS can send a signal to shut off or deactivate the blower 325.

From the heater core 300, the heated water flows through a one-way valve 190 before returning back to the radiator tank 200. Thus, a heating loop can be formed from the radiator tank 200, the heat exchanger 250, the heater core 300, and back to the radiator tank 200. The one-way valve 190 can be provided downstream of the heater core 300 to prevent water from the water inlet 106 to enter the heater core 300 or flow through the water outlet 108 other than through the mixing valve 150. The one-way valve 190 can ensure only heated water leaving the heater core 300 can pass through the mixing valve 150.

As shown, the pump 170 is located downstream of the radiator tank 200 in the blower compartment 102 b, but can be located in the burner compartment 102 c, the radiator compartment 102 a along the heating loop, or elsewhere within the housing. In one example, the pump 170 is an electric activated water pump controlled by a microprocessor of a control board 350 and operated to circulate the water through the heating loop when the hydro-furnace 100 is powered on and a temperature of the water in the radiator tank is below a minimum tank temperature to provide hot water and/or heated air.

The pump 170 can continually circulate the water through the heat exchanger 250 until the average temperature of the water in the radiator tank 200 reaches a threshold temperature, such as, for example, 160 degrees F. or some different set point temperature. Once the average temperature of the water in the radiator tank 200 reaches the threshold temperature, such as 160 degrees F., the pump 170 and the burner 275 can shut off. If the water in the radiator tank 200 falls below a minimum tank water temperature, such as 140 degrees F., the pump 170 and the burner 275 can switch on until the average temperature of the water in the radiator tank 200 returns back to the threshold temperature, such as 160 degrees F. Thus, the water in the radiator tank 200 can be maintained between 140-160 degrees F.

As hot water is being dispensed through the hot water outlet 108, water from the water supply can enter the radiator tank to replace the dispensed hot water. Because the newly introduced water is typically lower in temperature than the temperature of the water in the radiator tank 200, the new combined temperature drops from the previous tank temperature. When the temperature of the water in the radiator tank falls below the minimum tank temperature, the pump 170 and the burner 275 are activated to generate heat and produce additional heated water until the minimum tank temperature is reached. The hydro-furnace 100 is capable of producing hot water as hot water is continually used. Thus, the hydro-furnace 100 can also function as a tankless water heater.

Turning now to FIGS. 3-6, the hydro-furnace 100 is shown without the housing panels to more clearly depict the part or components mounted inside the housing. More clearly shown are the water supply inlet 106 and the water outlet 108, which are in line with each other and connected with the tubing 114. As shown and further discussed below, the water supply inlet 106 and the hot water outlet 108 can be located externally of the housing 102, such as externally of the left side of the hydro-furnace 100 of the housing 102 for quick access by a user. The gas inlet 104 can be located on the right side of the hydro-furnace 100.

Optionally, tubing and mechanical and electrical components can be located, at least in part, outside of the panels of the housing 102 to facilitate assembly and maintenance, among other things. Incoming water or water to be heated from a water supply or source can enter the hydro-furnace 100 through the water inlet 106 extending out of the housing 102. In one example, the water inlet 106 can be a threaded male connector for engaging a threaded female connector from a water supply. In another example, the water inlet 106 can be a smooth pipe with or without a hose barbed end to receive a hose or tubing connected to the water supply. A clamp can further secure the hose or tubing to the water inlet 106.

As shown, the water inlet 106 can have a standard fitting to readily accept a water feed line or inlet water source. For example, the water supply inlet 106 can comprise an industry standard connection fitting for attaching to a water supply or cold water supply line. The hot water outlet 108 similarly can comprise an industry standard connection fitting for attaching to plumbing lines that then carry heated water to user stations, such as to sinks and baths/showers located elsewhere in the RV on which the hydro-furnace 100 for the RV is mounted. In one example, the water supply inlet 106 and hot water outlet 108 can include a quick connect coupling or a threaded collar.

Unlike a water heater or furnace installed in a permanent structure, such as in a home which has a generally stable water supply temperature and pressure, an RV with a hydro-furnace 100 moves from water supply source to water supply source when on the road travelling from point A to point B, etc. The hydro-furnace 100 for the RV should be able to produce water at the desired temperature from widely varying water supply temperatures while still maintaining a relatively small size or profile to fit within the portable environment of the RV.

The water inlet 106 inside the housing 102 can transition into a multi-flow fitting 130, such as a four way pipe fitting or a four way tee, used to combine and/or divide fluid flow. In an example, the multi-flow fitting 130 can be four individual fittings oriented 90 degrees apart to for a four way tee. However, multiple back to back tees can be used to split the flow into multiple streams. In one example, the water inlet 106 is coupled to a first fitting of the four way tee 130, a hot water return line 132 from the heater core 300 is coupled to a second fitting of the four way tee 130, the radiator tank 200 is coupled to a third fitting of the four way tee 130, and a mixing valve 150 is coupled to a fourth fitting of the four way tee 130 via a cold water output line 134. Thus, the four way tee 130 allows water from the water inlet 106 to flow into the radiator tank 200 and to the mixing valve 150, which is further discussed below.

The radiator tank 200 is located in the radiator compartment 102 a and can store water received from the water inlet 106 and the hot water return line 132. The temperature of the water inside the radiator tank 200 can be monitored by one or more temperature sensors and maintained and controlled at an optimum tank temperature, such as between 140-160 degrees F., using control circuitries, a controller, or a control board, as further discussed below with reference to FIGS. 8 and 9.

As the temperature of the water inside the radiator tank 200 increases, so does the temperature of the radiation tank 200. A tank emergency cutoff thermostat (TECO) 351 for preventing the temperature of the water inside the radiator tank 200 from increasing past a maximum tank water temperature, can be positioned on a surface of the radiator tank 250. In one example, the maximum tank water temperature is 170 degrees F. In another example the maximum tank water temperature can be other than 170 degrees F. In one embodiment, the TECO 351 can be a disc thermostat that prevents the burner 275 from firing when the temperature of the water in the radiator tank 200 exceeds the maximum tank water temperature.

As previously mentioned, return air can be pulled by a blower 325 located in the adjacent blower compartment 102 b, from both the upper radiator chamber, which draws the return air from outside the hydro-furnace 100 through the upper return air vent 107, and the lower radiator chamber, which draws the return air from outside the hydro-furnace 100 through the lower return air vent 109. In one example, the radiator tank 200 can be located in the lower radiator chamber of the radiation compartment 102 a. Thus, the return air in the lower radiator chamber can be preheated by convective heat transfer from the radiator tank 200 as it travels from the radiator compartment 102 a to the blower compartment 102 b.

The radiator tank 200 can comprise a radiator tank body 205 having a storage space configured to store the heated water, an inlet radiator cover 215 at an inlet end of the radiator tank body 205, and an outlet radiator cover 220 at an outlet end of the radiator tank body 205. A plurality of fins 210 extending from the exterior of the radiator tank body 205 may also be provided to increase convection from between the radiator tank 200 and the return air in the radiator compartment 102 a.

The inlet radiator cover 215 can be similar or identical to the outlet radiator cover 220. The inlet and outlet radiator covers 215, 220 can be circular and sized to fit at opposite ends of the radiator tank body 205 to cover the interior space of the radiator tank body 205. A watertight seal such as an O-ring or gasket can be provided between the radiator covers 215, 220 and the radiator tank body 205. An inlet opening 217 through the inlet radiator cover 215 can allow water from the inlet and/or the hot water return line 32 from the heater core 300 to flow inside the radiator tank body 205. An outlet opening 222 through the outlet radiator cover 220 can allow water from inside the radiator tank body 205 to flow to the heat exchanger 250.

A size or diameter of the inlet and outlet openings 217, 222 can be smaller than a size or diameter of the interior cavity or bore of the radiator tank body 205 so that a volume of water can be maintained inside the radiator tank body 205. In one example, the radiator tank body 205 can store 2-4 gallons of water. In other examples, the tank body can store a different volume of water. The location of the inlet opening 217 and the outlet opening 222 can affect water flow and temperature mixing inside the radiator tank body 205. In one example, the inlet opening 217 can be adjacent an outer perimeter of the inlet radiator cover 215, and the outlet opening 222 can be adjacent an outer perimeter of the outlet radiator cover 220, with the inlet opening 217 and outlet opening 222 diametrically opposed at opposite ends of the heat exchanger 250 to provide a longer path through the radiator tank body 205. This can ensure better mixing than a shorter direct path between the inlet and outlet openings 217, 222.

Referring to FIG. 4, water from the radiator tank 200 can exit out the outlet 222 and flow to the heat exchanger via a radiator tank output line 136. A pump 170 can be positioned inline and downstream of the radiator tank 200 along the radiator tank output line 136. In one example, the pump 170 can be located between the heat exchanger 250 and the radiator tank 200 along the radiator tank output line 136 inside the blower compartment 102 b. The pump 170 can be a standard electric driven water pump. The pump 170 can be controlled directly or indirectly by control circuitry as previously discussed and further below with reference to FIGS. 8 and 9. As described above, water is pumped out from the radiator tank 200 to the heat exchanger 250 where it is heated and passes through the heater core 300 before being dispensed through the mixing valve 150 to the water outlet 108 and to a faucet or shower and/or return back into the radiator tank 200, thus forming the heating loop. The pump 170 can actively circulate the water until the radiator tank 200 reaches some set point, such as 160 degrees F., at which time the burner 275 can switch off. The pump 170 can be shut off simultaneously with the burner 275 or a short time thereafter. In other examples, the pump 170 can be positioned anywhere along the heating loop as described above.

A low temperature sensor (LTS) 354 (FIG. 8) or alternatively an input temperature probe (Tin) 355 (FIG. 9) for measuring the temperature of the water can be connected inline and downstream of the radiator tank 200. The LTS 354 can be a disc thermostat that provides a heat request signal to the burner 275 when the water temperature in the radiator tank 200 drops below a minimum tank water temperature. The Tin 355 can be a thermistor probe that monitors the water temperature. In one example, the minimum tank water temperature is 140 degrees F. In the illustrated embodiments, the LTS 354 or Tin 355 can be located downstream of the radiator tank 200 before reaching the pump 170 or downstream of the pump 170 at or before the heat exchanger 250. Other sensors can be used or a combination of sensors can be used to read and provide input to the controller to control the burner 275.

The radiator tank output line 136 can be coupled to a heat exchanger tubing 252 as illustrated in FIGS. 6A and 6B. The heat exchanger tubing 252 can wrap around the exterior of the heat exchanger 250, which can be a conductive body having a skirt or a plenum 251. The plenum 251 and the heat exchanger tubing 252 can be made of a conductive material, such as aluminum, copper, copper alloy, brass, brass alloys, or other conductive metals. In other embodiments, the plenum 251 and the heat exchanger tubing 252 may be made from other corrosive resistant materials, or plated or coated with corrosive resistant material, that are able to withstand the direct or indirect heat of the burner 275.

The heat exchanger tubing 252 can wrap around the plenum 251 so that water flows from a bottom end 253 of the plenum 251, elevation-wise, towards a top end 255 of the plenum 251 inside the tubing, and by conduction is heated by the plenum 251 which then heats the water running through the heat exchanger tubing 252, similar to a preheat. Because both the plenum 251 and the heat exchanger tubing 252 can be made from a conductive material, heat energy is transferred by conduction from the plenum 251 to the heat exchanger tubing 252 and from the heat exchanger tubing 252 to the water running therein. As a result, the water running around the plenum 251 inside the tubing is pre-heated before entering the heat exchanger 250. The water in the heat exchanger tubing 252 then enters the heat exchanger 250 so as to be heated by the heated gas from the burner 275, as further discussed below.

The plenum 251 can have an opening with a passage extending from the bottom end 253 to the top end 255. Within the plenum 251, a plurality of spaced apart internal fins (not shown) can be located in the opening between the bottom end 253 and the top end 255 to provide additional heat transfer paths to the heat exchanger 250. In one example, the internal fins are located near the top end 255 to provide space for the burner 275. The internal fins can be closely spaced or loosely spaced inside the plenum 251 to form baffles or channels for the flow of heated air from the bottom end 253 of the heat exchanger 250 and then rising through the internal fins and out the top of the heat exchanger 250, elevation-wise. The number of internal fins and the surface area of each of the internal fins can depend on the desired heat exchange rate by convection, conduction, and radiation exchanging with the interior run line of the heat exchanger tubing 252.

The heat exchanger tubing 252 passes through the internal fins and wherein U-shaped returns are provided on outer surfaces on opposite sides of the plenum 251 to connect the parallel tubing sections in a serpentine fashion within the interior space of the plenum 251. Thus, the heating pipe 252 can form continuous passes through the opposite sides of the plenum 251 and the internal fins to maximize the heat transfer from the internal fins to the heat exchanger tubing 252 to heat the water flowing therein. The number of fins and the total tubing length passing inside the plenum 251 can be selected to control the residual time of water travelling through the plenum 251 and the amount of heat transferring directly from the burner 275 to the plenum 251 and from the burner 275 to the fins and then to the heat exchanger tubing 275.

An exhaust system 257 comprising an exhaust conduit can be provided to collect exhaust fumes rising from the burner 275 and direct the exhaust fumes away from and outside the burner compartment 102 c through the burner outlet vent 105. As shown, the exhaust system 257 is positioned at the top of the plenum 251 and coupled directly to the top end 255 of the plenum 251. The exhaust system can extend horizontally towards the burner outlet vent 105. The exhaust system 257 can have a larger opening at the output end to provide an open flow path to the burner outlet vent 105 for the combustion byproducts.

The exhaust system 257 can be sealed to ensure the combustion byproducts flow directly out the burner outlet vent 105. An exhaust fan powered by an exhaust fan motor may also be provided to assist directing the exhaust fumes through the burner outlet vent 105. The exhaust fan may be connected to a microprocessor of a controller such as the DSI board explained further below. The DSI board can operate the exhaust fan motor to turn the exhaust fan on and off based on signals sent to the microprocessor from one or more sensors. For example, whenever the burner is activated to burn fuel, the exhaust fan is also activated to exhaust gas. The exhaust fan can also be activated when the burner is not in service to move air through the system for cooling or venting purposes. A vent duct may also extend away from the housing 102 surrounding the burner outlet vent 105 to direct the exhaust fumes away from the hydro-furnace 100 and the RV. The exhaust fan may be located inside the vent duct instead of inside the housing 102.

Additional ducting may be provided to direct the exhaust gas through the burner outlet vent 105 and out, such as out an opening to an exterior of the mobile or recreational vehicle. In some examples, an induced draft fan, a force draft fan, or both can be incorporated to move gas through the hydro-furnace 100.

In some examples, inlet and outlet headers are provided within the heat exchanger 250. For example, the heat exchanger tubing 252 can direct inlet water to the inlet header that then separates the single inlet feed line into multiple parallel run lines inside the heat exchanger 250. The multiple run lines are then routed to an outlet header that then consolidates the various run lines into a single outlet line, which then exits the heat exchanger 250 and flow into the discharge or outlet line 124.

In the embodiment shown, the heat exchanger tubing 252 wraps around the plenum 251 of the heat exchanger 250 three times in the form of loops, such as continuous loops or in sections that are joined. In other embodiments, the heat exchanger tubing 252 may have fewer than three loops wrapping around the plenum 251 or more than three loops wrapping around the plenum 251. The length of the heat exchanger tubing 252 and the number of loops formed or wrapped around the heat exchanger 250 can depend on the residual time desired to route the water through the heater, the number of tie-ins needed to connect the various component, and the desired preheat, among others.

The burner 275 can be positioned immediately adjacent the heat exchanger 250 and provide the heating source to heat the exchanger 250. In an example, the burner 275 is positioned below the heat exchanger 250, elevation-wise, so that hot air and combust gas generated from the burner rise through the heat exchanger 250. In an example, the burner 250 can have a wide tip having multiple gas discharge holes to provide a large distributed flame profile. The tip can comprise a plurality of plate-like structures positioned side-by-side with each plate having a plurality of discharge holes formed on an edge thereof for gas flow. The tip can alternatively have a circular ring shape, a rectangular shape, an elliptical shape, a square shape, or other shaped tips provided the number of discharge holes are selected to produce sufficient BTU for a given gas type and gas pressure.

The burner 275 can comprise a burner pad 276 extending at least partially into the plenum 251 through the opening at the bottom end 253 to provide heat inside the plenum 251. The amount of heat provided to the plenum 251 to heat the water circulating in the heat exchanger tubing 252 depends on the power output of the burner 275. The burner 275 generates heat by the combustion of gas. The fuel or gas is supplied to the burner 275 through the gas inlet 104 extending outside of the housing 102. The gas is directed from the gas inlet 104 to a fuel or gas control valve 278, which is configured to control the flow of gas into a burner pad 276 located beneath or at least extending partially inside the boiler heat exchanger 250 through the bottom end 253 of the boiler heat exchanger 250. In one embodiment, the gas control valve 278 can open and operate in one of two stages: a high stage (HI) and a low stage (LO), as discussed further below. When not in use, the gas control valve 278 can cut off the supply of gas or shut off. When the gas control valve 278 is on HI, the output of gas is at a high BTU rating, and when the gas control valve 278 is on LO, the output of gas is at a lower BTU rating. Alternatively, the can control valve 278 can be a variable gas control valve.

The multiple gas discharge holes of the burner pad 276 can be a series of nozzles (not shown) for the gas to pass therethrough. An ignition control box 280 can comprise a direct spark ignition (DSI) board 285 having a microprocessor and ignition control electronics including a spark igniter, which can be controlled to ignite the gas leaving the nozzles to combust the gas and produce heat. The ignition control box 280 and the gas control valve 278 can be controlled directly or indirectly by control circuitry as discussed below with reference to FIGS. 8 and 9.

Referring now to FIG. 6A, the heat exchanger tubing 252 can exit the heat exchanger 250 and connect to an input port 302 of the heater core 300 via a connector tubing 138. In the illustrated embodiment, the heat exchanger tubing 252 exits the heat exchanger 250 near the top end 255 of the heat exchanger 250. A boiler heat exchanger emergency cutoff thermostat (BECO) 356 (FIGS. 8 and 9) can be provided to detect whether the temperature of the water leaving the heat exchanger 250 exceeds an absolute maximum heated temperature to cut power to the burner 275. In one example, the absolute maximum heated temperature is 185 degrees F. with other maximum values contemplated, such as lower or higher than 185 degrees F. The BECO 356 can be connected inline and downstream of the heat exchanger 250. In one example, the BECO 356 is a disc thermostat that turns off the burner 275, or sends signals to the controller to then turn off fuel to the burner, when the water temperature at the output of the heat exchanger 250 exceeds 185 degrees F. In an example, when the max temperature is sensed, the emergency shut off valve is activated to block all fuel to the burner. When the burner 275 is not on, the pump 170 can also turn of. Conversely, the pump 170 can be operational when the burner 275 is on.

A high temperature sensor (HTS) 357 (FIG. 8) or an output temperature probe (Tout) 358 (FIG. 9) for monitoring the temperature of the water downstream of the heat exchanger 250 can be placed adjacent, downstream or upstream, to the BECO 356 to stop the burner 275 when the water temperature at the output of the heat exchanger 250 exceeds a maximum heated water temperature. In one example, the maximum heated water temperature can be 175 degrees F.

Referring now to FIG. 5, the heater core 300 transfers heat from the water to the return air supplied by the blower 325. The heater core 300 comprises a core body 301 having a box like shape mounted in the blower compartment 102 b on a panel separating the radiation compartment 102 a from the blower compartment 102 b. The core body 301 is shown having a hollow rectangular shape with a rear opening 302 facing the radiator compartment 102 a and a front opening 303 facing towards the blower 325. Flanges 304 can extend from each side of the rear opening 302 (FIG. 2) to attach to the central panels of the radiator housing 110 and/or main housing 120. The rear opening 302 can communicate to the radiator compartment 102 a, and more specifically, the upper and lower radiator chamber through the upper rectangular cutouts 111, 121. The front opening can be coupled directly to a suction port 326 of the blower 325.

The blower 325 circulates air from the interior space of the mobile vehicle or RV through the radiator tank 200 and the heater core 300 to the air plenum 340 and back to the room through air ducts 345. The blower 325 has a suction port 326 to draw in air and a blower port 327 to blow air out. Thus, the blower 325 can function as a vacuum. Alternatively, the ports can be reversed, or a different type of blower 325 can be used, as desired.

A room thermostat (RTS) 360 outside the hydro-furnace 100 can be preprogrammed or operated by a user to generate and transmit a heat request for air heating or space heating. The RTS can be connected to control circuity of the hydro-furnace 100 to activate the pump 170, the burner 275, and the blower 325 when powered “ON”. The RTS can also send signals to the control circuitry of the hydro-furnace 100 to stop the blower, pump, and/or burner when an interior set point is reached.

In one embodiment, the gas control valve 278 can be set between a high setting (HI) and a low setting (HI). Alternatively, the gas control valve 278 can be variable. The gas control valve 278 can be normally set on HI until the water in the radiator tank 200 is within the minimum tank water temperature and the threshold temperature, such as between 140-160 degrees F., or above the threshold temperature, at which time the gas control valve 278 can switch to LO.

In one example, when the blower 275 is activated by the RTS 360, the power to the blower 325 is applied to this connection and reduces the output of gas to the lower BTU rating. That is, the gas control valve 278 is on LO. The burner 275 can also be activated by the RTS when the RTS is not powered “ON” and the water temperature in the radiator tank 200 falls below the minimum tank water temperature, such as, in one example, 140 degrees F. Thus, when water is to be heated or air is to be heated, but not both, the gas control valve 278 can operate on LO. When both water and space are to be heated simultaneously, the gas control valve 278 can be on HI. In an example, the LO setting can be about 12K to about 18K BTU, and the HI setting can be about 35K to about 37K BTU. A relay (R) 359 can prevent the gas control valve 278 from switching to LO if both the water heating and space heating are used simultaneously. The pump 170 can be operating continuously while the burner 275 is on.

Within the core body 301 of the heater core 300, a plurality of spaced apart fins 305 are provided. The fins 305 can be closely spaced or loosely spaced inside the core body 301 to form baffles or channels for the flow of return air from the radiator compartment 102 a through the heater core 300 generated by the suction of the blower 325. The number of fins can depend on the desired heat exchange rate by convection, conduction, and radiation exchanging with the interior run line of the heater core tubing 310. The heater core tubing 310 passes through the fins and wherein U-shaped returns are provided on opposite exterior surfaces of the heater core body 301 to connect the parallel tubing sections in a serpentine fashion within the interior space of the heater core 300. The number of fins and the total tubing length passing inside the heater core 300 can be selected to control the residual time of water travelling through the heater core 300 and the amount of heat transferring directly from the heater core tubing 310 to the fins and then to the return air. In one embodiment, the heater core tubing 310 and the fins are made from a highly conductive material, such as copper, brass, or their alloys.

A pneumatic resistance screen 315 can be provided inside the heater core 300 between the fins 305 and the front opening 303 to increase the efficiency of the heater core 300. The pneumatic resistance screen 315 can reduce the velocity of the return air pulled into the suction port 326 of the blower 325 to increase the resistance and therefore heat transfer from the heater core tubing 310 and the fins 305 to the return air as it passes through the fins 305 into the blower 325.

A three-way tee 131 can bifurcate the line from the heater core 300 to direct the heated water to the mixing valve 150 and back to the radiator tank 200 through the one-way valve 190 and the hot water return line 132. In one example, if hot water is not being used, such as not exiting the water outlet 108, then the water will circulate back into the radiator tank. If some hot water is used, then only the remaining portion of hot water not leaving the hydro-furnace 100 will be returned to the tank. As hot water leaves the hydro-furnace 100, water from the water supply can flow into the water inlet 106 to replace the heated water leaving the hydro-furnace 100. Thus, the amount of water held in the hydro-furnace 100 can remain relatively constant. FIGS. 8 and 9 illustrate two different embodiments of a control system for controlling operation of the hydro-furnace 100. FIG. 8 illustrates an electro-mechanical control system based on a direct spark ignition (DSI) board 285 to provide the required safety features. FIG. 9 illustrates an electronic control system which uses a DSI board 285 and a separate electronic control board that monitors the water temperature using thermistor probes rather than thermostats at various locations.

Referring to FIG. 8, the ignition control box 280, which can house the DSI board 285, can comprise a control box base 281 and a cover 282. The cover 282 can be flush with the surface of the housing 102 or extend partially out from the housing surface. Alternatively, the cover 282 can remain inside the housing 102. In one embodiment, the electro-mechanical control system is similar to those found in standard furnaces and water heaters. The DSI board 285 is a microprocessor based control board that operates all functions of the hydro-furnace 100 and provides terminal connections for power, such as +12V, grounding, the gas control valve 278 to open and shut off the gas to the burner 275, ignition terminal for the spark igniter to light the burner, a remote indicator (LGT) to provide feedback on the hydro-furnace 100 operation and possible faults, and a safety loop to verify that the TECO 351 and BECO 356 are not open. The LGT can provide feedback and alerts in the form of LEDs located on the cover 282 of the ignition control box 280, a surface of the housing, or a control panel located away from the housing 102. Optionally, an audible alarm may be incorporated to provide alerts.

A DSI board 285 provided herein can be a microprocessor based control board that can operate all the function of the hydro-furnace 100 according to safety and regulation standards and provide connections and controls for a sufficiently voltage for activating the ignition to the burner, a ground connection, the control of the gas valve 278 to open, shut off, and the control of gas flowing to the burner 275, remote indicate (LED) power to provide feedback on operation of the hydro-furnace 100 and possible faults, and safety loop to verify that the TECO and BECO thermostats are not open, among others. The power terminal of the DSI board can be connected to a DC power supply source, such as the battery power supply source of the RV via a power cable. The grounding terminal can be connected to a grounding cable to the RV to ground the circuit. The DSI board 285 and the microprocessor in the DSI board 285 of the hydro-furnace 100 can accept different voltages, such as 12 Volt DC to 24 Volt DC. Generally, 12 Volt DC can be produced by the on-board power system of the RV to power various auxiliary devices. The power can be tied or linked to the ignition system or supplied from a battery bank with fulltime power, as is well known in the RV industry. The battery bank that supplies fulltime power can be charged by the vehicle's generator or by plug-in AC power when the RV is plugged into an AC source.

In addition to the DC connector port discussed above, an I/O connector port can be used to set control parameters for the controller. Like the DC connector port, the I/O connector port can be a passage or bore through the housing 102 having a plastic ferrule or liner that allows one or more cables to pass therethrough for connections between the electric system of the water heater, such as the microprocessor, and a control panel, which can be mounted remotely from the hydro-furnace 100, such as near the kitchen, bathroom, or the vehicle dashboard. Power may be supplied to the thermostats and sensors, such as the TECO, BECO, LTS, and HTS, through the DSI board 285 or separately from the DC power source of the RV.

The ignition terminal can be provided for the ignitor high voltage wires, which supply the necessary power to ignition control electronics including the ignition control spark to supply the ignition source for the burner 275.

The RTS 360 can be connected to the DC power supply source, the relay (R) 359, the blower 325, the thermostats and temperature sensors, and the pump 170.

Various functions of the hydro-furnace 100, such as set temperature, water flow rate, and air flow rate, may be controlled by the DSI board 285. The microprocessor in the DSI board 285 can act as a gateway for receiving signals and data from the various sensors and is programmed to control operation of various components of the hydro-furnace 100 based on the received signals and data, as further discussed below. For example, based on the temperature data received from one of the thermostats or probes, the microprocessor can send control signals to the gas control valve 278 to modulate gas flow feeding the burner 250.

The controller or DSI board 285 of the hydro-furnace 100 can be connected to an onboard fulltime DC power supply of the RV and not dependent on the car ignition system. By connecting to the vehicle's fulltime power, the DSI board 285 is always powered and various set points using a control panel and various parameters and data used by the microprocessor can be maintained or saved. In other examples, the DSI board 285 is equipped with auxiliary memory that stores set points and parameters and can retain the information even when power is disconnected to the DSI board 285. When auxiliary memory is incorporated, the DSI board 285 can be supplied with the vehicle's generator power.

Referring now to FIG. 9, the electronic control system is similar to the electro-mechanical control system of FIG. 8, except that an electronic control board 350 is used to monitor the water temperature using thermistors instead of thermostats. In an example, the LTS 354 and HTS 357 of the electro-mechanical control system of FIG. 8 are respectively replaced by the thermistor probes Tin 355 and Tout 358 of the electronic control system. The Tin probe 355 can be placed at the input of the heat exchanger 250 and the thermistor probe Tout 358 can be placed at the output of the heat exchanger 250 downstream of the BECO. The electronic control system can further include a thermistor probe T1 361 located at the top of the radiator tank 200 and a thermistor probe T2 362 located at the bottom of the radiator tank 200 to determine the state of mixing of the water and, indirectly, the water heating function. In another example, the

T1 probe 361 can be located at the upstream end of the radiator tank 200 and the T2 probe 362 can be located at the downstream end of the radiator tank 200. The electronic control board 350 can directly activate the pump 170 and the blower 275 based on precise values measured by thermistor probes T1 361, T2 362, Tin 355, Tout 356, which can be directly connected to the electronic control board 350.

The DSI board 285 in the electronic control system is also similar to the electromechanical control system of FIG. 8, except that the power terminal is now connected to the electronic control board 350 instead of the thermostats and temperature sensors. The RTS 360 can also be connected directly to the electronic control board 350. Thus, operations in the electronic control system of FIG. 9 can be handled by the electronic control board 350. More precisely, a microprocessor in the electronic control board 350 can receive and send signals to power and control the components in the hydro-furnace.

Referring to FIG. 10, another embodiment of a hydro-furnace 100 is shown. The hydro-furnace 100 can be similar to the hydro-furnace 100 of FIG. 1 with a few exceptions. In the present embodiment, the heated water can be stored in a coil reservoir 240 instead of a radiator tank 200. The coil reservoir 240 can be a tubular structure that can extend between opposite sides of the radiator compartment 200 a in a serpentine fashion with U-shaped ends connecting parallel tubing sections extending in opposite directions within the interior space of the plenum 251. As shown, the coil reservoir 240 forms a plurality of loops confined within the lower radiator chamber of the radiator compartment 200 a. Each of the plurality of loops can be spaced apart from each other to allow return air to be drawn outside the hydro-furnace 100 from the lower return air vent 109 through each of the loops or tubing sections. Return air in the Heat can be transferred from the coil reservoir 240 into the return air inside the radiator compartment 102 a or lower radiator chamber before being drawn through the heater core 200 into the blower 325. Thus, like the radiator tank 200, the coil reservoir 200 can pre-heat the return air to improve heating efficiency of the hydro-furnace 100.

In still other examples, additional probes and/or sensors can be connected in-line with the various tubing and lines of the hydro-furnace 100 in either system for sensing and controlling or regulating other flow functions in either the electro-mechanical system or the electronic control system. Other sensors such as pressure and flow sensors may be added for more advanced functions to improve performance, such as user selection of performance parameters, troubleshoot capabilities to identify various system failures, warnings to the user of potential failures, and remote control of all features from a panel or handheld unit or via internet access. The various connections can be threaded, welded, by mating flanges, or combinations thereof. In some examples, a threaded bore is provided on a side of a fitting, such as a threaded socket or a threaded thermowell, for receiving a probe, which can include a thermostat, a flow sensor, or other sensing devices. Optionally, welding may be used to connect the various components and tubing sections.

As available space can be limited in RVs, the present disclosure provides for modularization of the components of the hydro-furnace system 100. For example, the system 100 can be generally separated into segmented sub-systems that can be stored or mounted in spaced apart configurations. In an example, the hydro-furnace system 100 can be separated into a water heater module 1110, a tank module 1120, and a hydro-furnace module 1130. The modules can be located separately from one another, such as spaced from one another in different segmented structures, throughout the RV, with necessary connections between them. In this way, the components of the hydro-furnace 100 system can be installed in small spaces in the RV that already exist and are relatively easier to access without the need for designing a sufficiently large space for a single unit system. Additionally, the modularization can allow for modular sizing of components to fit the needs of the specific RV. For example, a larger RV may require a large storage tank 200 or blower 325. In some examples, the hydro-furnace system 100 can be separated into two or more sub-systems that can be mounted in spaced apart configurations.

The separation of the components can provide a benefit for better isolation of the water heater unit and the exhaust system, which can produce emissions byproducts from the burner 275 that can be harmful if introduced into the interior of the RV. The other benefit, as previously described, is the flexibility of storing sub-components or sub-systems in multiple smaller spaces throughout the RV instead of a single large space.

FIGS. 11-15 show a schematic flow diagram and components of a modularized hydro-furnace system as might be installed on an RV or other mobile vehicles, such as a boat.

FIG. 11 illustrates a schematic layout for a modularized hydro-furnace system 100 using an electronic control system. FIGS. 12 and 13 illustrate exemplary implementations of the different sub-systems. The hydro-furnace system 100 can have a water heater module 1110 that contains a water heater or water boiler 275. The water heater can be controlled by an electronic control board 350 acting in response to a thermostat 360 that monitors the water temperature using thermistor probes 1152. The electronic control system can use a DSI board as described in FIGS. 8 and 9 to control the water heater.

The room thermostat 360 can generate a heat request for space heating as desired by a user. The electronic control board 350 can receive the heat request from the room thermostat 360 and control the components of the hydro-furnace system 100 as necessary to provide the requested heat.

The electronic control board 350, though the DSI board, can control a burner 275 in the water heater module 1110 as understood from at least FIGS. 4, 8, 9, 12, and 13. The water heater module 1110 can receive water from a cold water source 106 or from the storage tank 200. In an initial state, the system is primed with water from the cold water source 106.

The water input into the water heater module 1110 can be heated and then either supplied as warm water through a warm water line 108 to the user or as heated water through the hydro-furnace water circuit 136 to provide heat to the RV.

From the water heater module 1110, the heated water can flow through the hydro-furnace water circuit 136 to the hydro-furnace module 1130. There, the heated water can flow through a heat exchanger 300. A blower 325 can move air across the heat exchanger to heat the air from heat transferred from the heated water. The blower 325 and the heat exchanger 300 are described further with reference to FIG. 15. The blower 325 can be controlled by the electronic control board 350. The heated air can then be distributed to the interior of the RV through the air vents 107 of the hydro-furnace module 1130. To improve the efficiency of the hydro-furnace module 1130, there can be provided a pneumatic resistance screen 315 in front of the heat exchanger 300. This can increase the efficiency of the heat exchanger 300 by increasing the residual contact time with the heat exchanger, such as by reducing the velocity of the air being moved by the blower 325.

After circulating through the heat exchanger 300 of the hydro-furnace module 1130, the heated water flows to the tank module 1120. There, the heated water flows through a one-way valve 190 before flowing into the tank 200 through a manifold 1128. Water from the tank 200 can then be recirculated to the water heater module 1110 through a downstream one-way valve 1124 by way of a pump 170 and a solenoid valve 1126. The pump 170 can actively circulate the water through the water heater module 1110 until the temperature of the storage tank 200 reaches a desired temperature. The temperature can be checked by way of a temperature probe 1152 downstream of the storage tank 200. The electronic control board 350 can control the pump 170, solenoid valve 1126, and blower 325 based upon the readings from the thermostat 360 and the temperature probe 1152.

The use of the one-way valves 190, 1124 prevent mixing of water in the different phases of the heating loop. Upon the water of the storage tank 200 reaching the desired temperature, the electronic control board 350 can shut off the burner 275 of the water heater module 1110.

As scalding is based on both temperature and duration of contact, the present disclosure provides for a mechanism to prevent the risk of scalding to the user. The water heater module 1110 can be designed to provide a predetermined amount of maximum heating to the water. In this way, the maximum temperature of water heated from the cold water source 106 can be limited to prevent scalding of a user when delivered for use through the water outlet 108.

To increase the heat of the water of the heating loop of the hydro-furnace system 100, the water from the heating loop can be continually cycled to water heater module 1110 and heated. In this way, the water can be heated to a higher temperature than that of the water delivered to the user.

Additionally, the heated water of the hydro-furnace system can be cut-off to the user by means of both the pump 170 and the solenoid valve 1126. Use of the solenoid valve allows for quick shut off of the flow of water from the stored water from flowing to the water heater. In this way, stored water that is hot is prevented from flowing into the water heater and being output to the customer. As a result of the shut off of flow from the stored water, the temperature of the water input into the water heater is limited by the inflow of cold water. The resulting heating of the water by the water heater is thereby limited in terms of the temperature of the water that can output to the user through the water outlet 108.

Furthermore an emergency cutoff (ECO) can be applied to the water outlet 108 for preventing the temperature of the water for a user from being improperly high even in the case of a malfunction.

In addition to the singular hydro-furnace module 1130, there can be additional hydro-furnace modules 1130 installed in the RV to provide zone specific heating as desired.

Embodiments of the water heater utilize a gas burner. However, it can also be envisioned that an electric water heater can also be used, which uses resistance heating coils or ceramic heating coils.

Additionally, as shown in FIGS. 8 and 9, the hydro-furnace system 100 can use alternative control systems, such as electro-mechanical.

FIGS. 12 and 13 show side and perspective views of the water heater module 1110, the tank module 1120, and the hydro-furnace module 1130.

The water heater module 1110 incorporates a burner 275 configured to heat water. The water heater module 1110 has a water input 1202 for receiving cold water 106 or circulating water from the hydro-furnace heating loop. The water input 1202 may include a manual water shut off valve. The water input 1202 may be on a first side of the housing 1112.

A fuel or gas inlet 104 for introducing fuel to the burner 275 in the water heater module 1110 is shown extending out from the first side of the housing 1112. A fuel or gas line can be connected to the gas inlet 104 to supply fuel, such as propane, to the burner 275. As shown, the gas inlet 104 is a male connector, however, the gas inlet 104 may be a female connector extending into the housing 1112, in which case a gas line having a male connector tip can engage the female connector to supply fuel to the burner 275. Pressure fittings may also be used to connect the various lines and components of the hydro-furnace system.

The water input can be coupled to a heat exchanger tubing 252 as further illustrated. The heat exchanger tubing 252 can wrap around the exterior of a heat exchanger 250, which can be a conductive body having a skirt or a plenum 251. The plenum 251 and the heat exchanger tubing 252 can be made of a conductive material, such as aluminum, copper, copper alloy, brass, alloys, or other metals.

The plenum 251 and the heat exchanger tubing 252 can be made from other corrosive resistant materials that are able to withstand the direct or indirect heat of the burner 275, or be plated or coated with a corrosive resistant material. The heat exchanger tubing 252 can wrap around the plenum 251 from a bottom end 253 of the plenum 251 towards a top end 255 of the plenum 251, elevation-wise, and by conduction is heated by the plenum 251 which then heats the water running through the heat exchanger tubing 252. This can be understood as being similar to a preheat. Because both the plenum 251 and the heat exchanger tubing 252 can be made from a conductive material, heat energy is transferred by conduction from the plenum 251 to the heat exchanger tubing 252 and from the heat exchanger tubing 252 to the water running therein. As a result, the water running around the heat exchanger 250 is pre-heated before entering the heat exchanger 250. The heat exchanger tubing 252 then enters the heat exchanger 250 so as to be heated by the heated gas from the burner 275, as further discussed below.

The plenum 251 can have an opening extending from the bottom end 253 to the top end 255. Within the plenum 251 of the heat exchanger 250, a plurality of spaced apart internal fins can be located in the opening between the bottom end 253 and the top end 255 to provide additional heat transfer paths. In one example, the internal fins are located near the top end 255 to provide space for the burner 275. The internal fins can be closely spaced or loosely spaced inside the plenum 251 to form baffles or channels for the flow of heated air from the bottom end 253 of the heat exchanger 250 and then rising through the internal fins and out the top of the heat exchanger 250, elevation-wise.

The number of internal fins and the surface area of each of the internal fins can depend on the desired heat exchange rate by convection, conduction, and radiation exchanging with the interior run line of the heat exchanger tubing 252. The heat exchanger tubing 252 passes through the internal fins and wherein U-shaped returns are provided on outer surfaces on opposite sides of the plenum 251 to connect the parallel tubing sections in a serpentine fashion within the interior space of the plenum 251. Thus, the heating pipe 252 can form continuous passes through the opposite sides of the plenum 251 and the internal fins to maximize the heat transfer from the internal fins to the heat exchanger tubing 252 to heat the water flowing therein. The number of fins and the total tubing length passing inside the plenum 251 can be selected to control the residual time of water travelling through the plenum 251 and the amount of heat transferring directly from the burner 275 to the plenum 251 and from the burner 275 to the fins and then to the heat exchanger tubing 275.

The water heated through the heat exchanger tubing 252 can then output through water output 1204 for delivery to the user or the hydro-furnace heating loop.

An electrical connector 1206 can be provided on the first side of the house 1112 also for connection of the electronics housed in the water heater module. The electrical connector 1206 may be a quick disconnect type. The electrical connector may be a plurality of connectors for different power and signal connections.

An exhaust system 257 comprising an exhaust conduit or duct can be provided to collect exhaust fumes rising from the burner 275 and direct the exhaust fumes and away from and outside the water heater module 1110 through the burner outlet vent 105. As shown, the exhaust system 257 is positioned at the top of the plenum 251 and coupled directly to the top end 255 of the plenum 251. The exhaust system can extend horizontally towards the burner outlet vent 105. The exhaust system 257 can have a larger opening at the output end to provide an open flow path to the burner outlet vent 105 for the combustion byproducts.

The exhaust system 257 can be sealed to ensure the combustion byproducts flow directly out the burner outlet vent 105. An exhaust fan 1208 powered by an exhaust fan motor 1209 may also be provided to assist directing the exhaust fumes through the burner outlet vent 105. The exhaust fan 1208 may be connected to a microprocessor of a controller such as the DSI board explained. The DSI board can operate the exhaust fan motor to turn the exhaust fan on and off based on signals sent to the microprocessor from one or more sensors.

Additional ducting may be provided to direct the exhaust gas through the burner outlet vent 105 and out, such as out an opening to an exterior of the mobile or recreational vehicle. In some examples, an induced draft fan, a force draft fan, or both can be incorporated to move gas through the hydro-furnace 100.

As further shown in FIG. 14, embodiments of the tank module 1120 of FIGS. 12 and 13 can have a water storage tank 200, an upstream one way valve 190, a downstream one way valve 1124, a pump 170, and a solenoid valve 1126. The tank module 1120 can contain only some of the components of the storage tank 200, the upstream one way valve 190, the downstream one way valve 1124, the pump 170, and the solenoid valve 1126. It is possible to place the upstream one way valve 190, the downstream one way valve 1124, the pump 170, and the solenoid valve 1126 in locations along the system between the water heater module 1110, the tank module 1120, and the hydro-furnace module 1130.

The storage tank 200 can store hot water for the hydro-furnace water circuit. The storage tank 200 can be an expansion tank and contain a resilient bladder certified for the operating temperature and pressure. The expansion tank can protect the RV water system from excessive pressure. The tank can be partially filled with air, the compressibility of which absorbs excess water pressure and/or water volume.

The storage tank 200 may be cylindrical in shape. The storage tank 200 may be oriented in an upright position, with an opening 1422 at one of the end surfaces 1420 a of the cylindrical shape, the end surface considered the downward oriented face when installed in an RV.

The storage tank 200 can have an alternative shape, such as rectangular, trapezoidal, or spherical. Also, the storage tank 200 can be oriented in different directions, such as having the cylindrical shape be oriented on its side 1420 b.

The opening of the storage tank 200 is coupled to a manifold 1128. The manifold 1128 can include an input side 1128 a connected to a tube 1129. The tube 1129 can convey the water from the input side 1128 a to an upper portion of the storage tank 200. The manifold 1128 can allow for water to exit the storage tank at the bottom of the storage tank at the opening 1422. In this way, the tank can have heated water conveyed to the top portion while relatively cooler, denser water at the bottom of the storage tank 200 can be drawn.

The manifold 1128 can include a chamber area 1128 c for the output side 1128 b. The chamber area 1128 c can connect to the downstream section of the piping of the system.

The manifold 1128 can be coupled to the storage tank 200 by way of corresponding threading. The coupling can also be achieved by way of corresponding lugs and grooves on the components. The coupling can also be achieved by way of a slip fit, and can also utilize a clamping ring over the slip fit.

Also, the illustrated manifold of FIG. 14 shows the manifold 1128 on the bottom surface of the storage tank 200. However, the manifold 1128 could be attached to side surfaces of the storage tank 200 instead of the bottom surface. The manifold 1128 can be attached to a lower portion of a side surface 1420 b near the bottom portion of the storage tank 200.

As shown in FIG. 14, the manifold 1128 can be a single connection point for both the input side 1128 a and outside side 1128 b. Additionally, the manifold 1128 can also be achieved with two connection points. The input side 1128 a can be separated from the output side 1128 b. Instead of a single connection point, the input side 1128 a can be attached to a second opening of the storage tank 200. In such a case, the opening for the input side 1128 a can be provided where convenient. The input side 1128 a in such a case can utilize a tube 1129 as necessary to convey water to the upper portion of the storage tank 200.

Alternatively, the opening may be provided at an upper portion of the storage tank 200, such that a tube is not necessary. Combinations of such a split connection could have the input side 1128 a and the output side 1128 b located on different surfaces of the storage tank 200.

The connections to the storage tank 200 can be arranged as necessary to fit the installation layout of the RV. For example, FIG. 14 illustrates an installation where the routing 1424 of pipe connecting the components results in a U-shape underneath the storage tank to minimize a footprint of the components for compactness. In this case, the upstream one way valve 190 can be in line with the manifold 1128. The routing can then go through a 90 degree bend to the downstream one-way valve 1124. After the downstream one-way valve 1124, the routing can then go through another 90 degree bend to the pump 170 and the solenoid valve 1126. Alterative bend configurations may be used as necessary to provide the convenient routing and attachment to the tank module 1120 when installed in the RV.

The upstream one way valve 190, by only allowing flow in a direction from the hydro-furnace module 1130 to the tank module 1120, prevents the potential mixing of water stored in the tank back to the water used for heating with the hydro-furnace module 1130.

Downstream of the manifold 1128, there is the downstream one way valve 1124 coupled in line with the pump 170, and the solenoid valve 1126. The downstream one way valve 1124 can prevent flow of water back into the storage tank 200 and mixing from downstream. The pump 170 can be powered to pump water from the storage tank 200 back to the water heater module 1110.

To minimize the risk of hot water being released, the solenoid valve 1126 can be used to control the flow of water from tank module back to the water heater module 1110. The solenoid valve 1126 can be used to provide a quick shut off mechanism to prevent flow of hot water stored in the storage tank 200. For safety, the solenoid valve 1126 can be of a type that is closed, or prevents flow, in an unpowered state, or off state. In this way, if there is a power loss to the solenoid valve 1126, the hydro-furnace water circuit is cut-off from providing hot water back to the water heater module 1110.

The tank module 1120 can have a housing 1122 to house the components of the tank module 1120. The housing may house just the tank 200. The housing may house some or all of the storage tank 200, the upstream one way valve 190, the downstream one way valve 1124, the pump 170, and the solenoid valve 1126. The housing 1122 can be shaped to substantially correspond to the storage tank 200. The housing 1122 can be shaped to correspond to a space in the RV or mobile vehicle. The components of the tank module 1120 can be retained inside the housing 1122 by being sized to fit or by retention methods such as mounting brackets. It is not necessary that each and every component be retained, but only that sufficient constraining is provided to minimize excess force from acting on the components. The use of a housing 1122 can allow for fitment inside the RV while using off-the-shelf components, which may be sized or shaped differently. For example, the expansion tank can be an off-the-shelf item that can be easily procured for different installation types. In this way, the mere change in dimensions for the house 1122 is much simpler and cheaper than attempting to custom design storage tanks 200 for different installations.

Further to FIGS. 12 and 13, FIG. 15 shows a hydro-furnace module 1130 configured to provide heated air to the RV. The hydro-furnace module 1130 can include a blower 325, a heat exchanger 300, and a pneumatic resistance screen 315. Other components or elements may be included with the hydro-furnace module, such as fittings, brackets, sensors, etc.

As shown in FIGS. 11 and 13, the hydro-furnace module 1130 can further include a housing 1132 to house the components of the hydro-furnace module 1130. The housing can provide air vents 107 to route the heated air into the interior of the RV.

The hydro-furnace module 1130 can receive heated water from the water heater module 1110 and route the heated water through the heat exchanger 300. The heat exchanger 300 transfers heat from the water to the air of the hydro-furnace module 1130, such that heated return air can be supplied by the blower 325. The heat exchanger can comprise a core body 301 with a box-like shape and core tubing 310.

In embodiments, the blower 325 can have a suction portion 326 and a blower port 327 to move the air. Alternatively, the ports can be reversed, or a different type of blower 325 can be used, as desired.

Within the core body 301 of the heat exchanger 300, a plurality of spaced apart fins can be provided. The fins can be closely spaced or loosely spaced inside the core body 301 to form baffles or channels for the flow of air through the heat exchanger 300 generated by the moving of air by the blower 325. The number of fins can depend on the desired heat exchange rate by convection, conduction, and radiation exchanging with the interior run line of the core tubing 310.

The core tubing 310 passes through the fins and wherein U-shaped returns are provided on opposite exterior surfaces of the core body 301 to connect the parallel tubing sections in a serpentine fashion within the interior space of the heat exchanger 300. The number of fins and the total tubing length passing inside the heat exchanger 300 can be selected to control the residual time of water travelling through the heat exchanger 300 and the amount of heat transferring directly from the core tubing 310 to the fins and then to the air.

In one embodiment, the core tubing 310 and the fins, are made from a highly conductive material, such as copper, brass, or their alloys.

In this way, the blower 325 can move air over the heat exchanger 300 to transfer the heat from the water to the air of the hydro-furnace module 1130. The heated air can then be provided through air vents 107 from the housing 1132 of the hydro-furnace module 1130 to the interior of the RV. The air vents can be provided to the housing 1132 such that there is necessarily some circulation of heated air inside the housing 1132 of the hydro-furnace module 1130 as the blower 325 operates. As such, the temperature of the air inside the house 1132 can be higher than ambient.

The present disclosure provides a modular RV water heating and furnace system having a heat exchanger housing that houses a heat exchanger and a burner, a hydro-furnace housing that houses a heater core and a blower, and a tank housing that houses a storage tank.

The burner provides heat to the heat exchanger and the heat exchanger heats water flowing therethrough it.

The blower moves air through the heater core, which is provided with the heated water from the heat exchanger.

The present disclosure provides a modular RV water heating and furnace system having a water heater, a heat exchanger, and a storage tank. The water heater heats input water and outputs the heated water. The heated water is then provided to the heat exchanger. The heat exchanger attached to a blower, which moves air through the heat exchanger, thereby warming the air. The heated water is then provided through a one-way valve from the heat exchanger to a storage tank. The heated water is then provided from a second one-way valve to a pump and a solenoid valve for circulation back to the water heater.

Methods of making the hydro-furnace systems, of using the hydro-furnace systems, and of installing the hydro-furnace systems as described herein are within the scope of the present invention.

Although limited embodiments of the hydro-furnace 100 for RV assemblies and their components have been specifically described and illustrated herein, many modifications and variations will be apparent to those skilled in the art. Accordingly, it is to be understood that the hydro-furnace 100 assemblies and their components constructed according to principles of the disclosed device, system, and method may be embodied other than as specifically described herein. The disclosure is also defined in the following claims. 

1. A water heater and furnace system for a recreational vehicle (RV) comprising: a housing comprising a plurality of panels defining an interior; a water inlet for receiving water from a water supply accessible through the housing; a hot water outlet accessible through the housing; a heat exchanger inside of the housing for heating water flowing through the heat exchanger; a burner inside of the housing to provide heat to the heat exchanger to heat the water flowing through the heat exchanger; a heater core coupled downstream of the hot water outlet of the heat exchanger; a blower for moving air across the heater core and delivering heated air outside the housing; a storage tank for storing water passed through the heater core; and a pump circulating water from the storage tank to the heat exchanger.
 2. The water heater and furnace system according to claim 1, further comprising a one-way valve downstream of the heater core and upstream of the storage tank to prevent water from flowing from the storage tank to the heater core.
 3. The water heater and furnace system according to claim 1, wherein the housing is sealed off from an interior of the RV.
 4. The water heater and furnace system according to claim 1, wherein the heater core comprises a plurality of spaced apart fins configured for convective heat transfer from the water running through the heater core to the fins to heat the air.
 5. The water heater and furnace system according to claim 4, wherein the heater core further comprises a pneumatic resistance screen to reduce the velocity of the air moved through the blower to increase the heat transfer from the heater core to the air as the air passes through the heater core.
 6. The water heater and furnace system according to claim 1, further comprising a mixing valve upstream of the hot water outlet and downstream of the water inlet and the heater core.
 7. The water heater and furnace system according to claim 1, further comprising a relay connected to the burner to prevent the burner from switching to a low setting from a high setting when the blower and the burner are both operating.
 8. The water heater and furnace system according to claim 1, further comprising an exhaust system coupled to a top end of the heat exchanger to collect combustion byproducts of the burner, and direct the combustion byproducts outside the housing.
 9. The water heater and furnace system according to claim 1, further comprising an air plenum to collect and deliver the heated air to heating ducts.
 10. The water heater and furnace system according to claim 1, further comprising: a solenoid valve coupled downstream of the storage tank and configured to control flow of the water from the storage tank to the heat exchanger.
 11. The water heater and furnace system according to claim 10, further comprising: a manifold attached to the storage tank, wherein the manifold is configured to convey water from the heater core to an upper region inside the storage tank.
 12. The water heater and furnace system according to claim 11, wherein the manifold is configured to convey the water from a lower region inside the storage tank to the pump.
 13. A method for regulating water outlet temperature and space heating of a hydro-furnace for a recreational vehicle (RV) comprising: circulating water from a water inlet to a heat exchanger for heating the water flowing through the heat exchanger and then directing the heated water through a heater core and then to a storage tank; heating air flowing across the heater core; heating the water running through the heat exchanger to produce heated water with a burner; pulling return air through the heater core with an air blower; heating the return air with the heated water to produce heated air; and circulating the water from the storage tank to the heat exchanger with a pump.
 14. The method according to claim 13, further comprising mixing the heated water with the supply water to produce hot water at a desired hot water temperature.
 15. The method according to claim 14, wherein the desired hot water temperature is 120 degrees F.
 16. The method according to claim 13, further comprising monitoring the temperature of water in the storage tank and sending a signal to a burner for heating the heat exchanger to turn on if the temperature of the water in the storage tank is below 140 degrees F.
 17. The method according to claim 16, further comprising activating the pump if the burner is on.
 18. The method according to claim 17, further comprising turning off the burner if the temperature of the water in the storage tank is greater than 160 degrees F.
 19. A water heater and furnace system for a recreational vehicle (RV) comprising: a heat exchanger configured to heat water received from a water supply; a heater core and a blower, the heater core being located remotely from the heat exchanger, the heater core being fluidly coupled to the heat exchanger by a first length of pipe, and the blower being configured to move air through the heater core and deliver heated air outside of a housing that houses the heater core and the heat exchanger; and a storage tank configured to store water passed through the heater core, the storage tank being located remotely from the water heater and the hydro-furnace, the storage tank being fluidly coupled to the heater core by a second length of pipe, and the storage tank being coupled to the heater exchanger to supply circulation water to the heat exchanger.
 20. The water heater and furnace system according to claim 19, further comprising: a solenoid valve coupled downstream of the storage tank and configured to control flow of the water from the storage tank to the heat exchanger. 